AUDI EPC LIGHT

AUDI HAS LOOMINITUS

Audi TT, A4 1.8T, A4 B5 1.8 Auto, 2.5 V6 Quattro B6, 1.6L A4 SE, 1.8L R4, Audi 8T0, Audi A6 C5,

Does your Audi occasionally have a hard time starting, yet finally starts just before you give up?  So when it starts, the EPC and ESP lights are on, then the engine cuts out. You restart and she idles rough and the check engine light comes on? After a while the EPC and ESP light go out, thereafter the car drives normal until the next time this happens. 

Or, as you are driving in manual mode, you noticed the ABS and ESP lights come on and suddenly your Audi's engine loses  power and goes into limp mode. You switch off, then restart, it idles rough but won't rev over 1500 RPM and she sounds like a tractor. You switch off once again, restart and the tractor is gone. So you get the Audi home driving at a snails pace, the next morning you start her and it seems like there was never any problems because she now idles and drives normally.

Or you are VCDS savvy, encountered an EPC light problem, cleared the fault and the next day it come back on. Several days later the EPC light comes on again, stays on and refuses to switch off. Once again you do a scan and you get a ton of  implausible  and intermittent DTC errors. 

Or your start the Audi, it idles for a few seconds then dies with the EPC light and ESP lights on. You clear the faults, lights go out. You drive the car for less than 3 km and it goes into limp mode. You disconnect the battery and reconnect and it seems fine thereafter. A few days later and the same thing occurs.

The Throttle body plug thats seem to haunt Audi owners.

What you have been experiencing is just a sampling of what the future holds. You Audi is suffering from "loominitus",  its loom is having issues, better known to auto electricians and motor mechanics as wiring harness issues. The culprit in all the above case is the 6 pin plug interfacing with the throttle body. Of late, this throttle body plug has become  quite trouble, you could almost call it common. Don't use contact spray on the plug. Ideally that portion of the loom needs to be replaced but since the female part of the plug is intermittent - hence faults come and go - it's worthwhile just replacing the plug and join the wires using ferrules and double crimp them. Cover the wires with shrink sleeving and avoid insulation tape because the engine heat will melt the PVC which will go sticky within days and  its messy.  

The troublesome Throttle body plug - connect thicker wires as per old plug.
Pin 1-blue/white stripe, Pin  2-purple/white stripe, Pin  3-white, Pin  4-blue/grey stripe, Pin  5-purple/black stripe, Pin  6-white/grey stripe

Throttle body replacement plug and colour coded wiring

I am so sorry to say, as the looms in the newer cars age, you should expect worse issues with the wiring harnesses.  See the list of sub loom components for the VW Polo here. Pieces of the harness that makes-up the whole.

Anyway should you scan your ECU, you will most probably find the following faults and perhaps others not listed here. The image below points to the troublesome plug.

18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
01314 - Engine Control Module
013 - Check DTC Memory - Intermittent
18084 - EPC Warning Lamp (K132) Circuit
P1676 - 35-00 - Electrical Malfunction
01176 - Key
65-10 - Unauthorized - Intermittent
01177 - Engine Control Unit
64-10 - Not Currently Testable - Intermittent
01119 - Gear Recognition Signal
             35-10 - - - Intermittent
18264 - Throttle Potentiometer (G69): Error Message from ECU
             P1856 - 35-10 - - - Intermittent
00258 - Mass Air Flow Sensor (G70)
              P0102 - 002 - Signal too Low - Intermittent
18039 - Accelerator Position Sensor (G79)
P1631 - 35-00 - Signal too High
18042 - Accelerator Position Sensor 2 (G185)
P1634 - 35-00 - Signal too High
00768 - Random/Multiple Cylinder Misfire Detected
              P0300 - 35-00 - -
16685 - Cylinder 1: Misfire Detected
             P0301 - 35-00 - -
16688 - Cylinder 4: Misfire Detected
              P0304 - 35-00 - -
16690 - Cylinder 6: Misfire Detected
              P0306 - 35-00 - -
16689 - Cylinder 5: Misfire Detected
             P0305 - 35- 00 - -
17953 - Throttle Valve Controller
P1545 - 35-10 - Malfunction - Intermittent
17981 - Left Engine Mount Solenoid Valve (N144)
              P1573 - 009 - Open Circuit
00473 - Control Module for Elect. Park/Hand Brake (J540)
              008 - Implausible Signal - Intermittent
01494 - Bulb for Parking Lamps; Left (M1)
             011 - Open Circuit
01504 - Bulb for License-Plate Light (X)
              009 - Open or Short to Ground - Intermittent
02255 - Voltage Measuring Lead from Vbat
             009 - Open or Short to Ground
16706 - Engine Speed Sensor (G28): No Signal
             P0322 - 35-00 -  -
00285 - ABS Wheel Speed Sensor; Front Right (G45)
008 - Implausible Signal - Intermittent
00283 - ABS Wheel Speed Sensor; Front Left (G47)
012 - Electrical Fault in Circuit - Intermittent
18057 - Powertrain Data Bus: Missing Message from ABS Controller
P1649 - 35-10 - - - Intermittent
16795 - Secondary Air Injection System: Incorrect Flow Detected
P0411 - 35-10 - - - Intermittent
17511 - Oxygen (Lambda) Sensor Heating; B1 S1: Performance too Low
P1103 - 35-10 - - - Intermittent
16497 - Intake Air Temp. Sensor (G42): Signal too High
P0113 - 35-10 - - - Intermittent
16955 - Brake Switch (F): Implausible Signal
P0571 - 35-00 - -

Audi on a rollback, notice the open bonnet

Audi on a rollback, number plate scratched for privacy

Audi on a rollback just before  peak hour in the afternoon.

Audi on a rollback enroute the service centre.

Audi on a rollback  

Audi TT, A4 1.8T, A4 B5 1.8 Auto, 2.5 V6 Quattro B6, 1.6L A4 SE, 1.8L R4, audi 8T0, Audi A6 C5,

Feel free to upload your VW, SKODA, SEAT & AUDI scans.

WIRING HARNESS ISSUES

AUDI ON A ROLLBACK

As I've mentioned in my previous blog, not only Volkswagen  vehicles but every new vehicle's wiring harnesses have undergone a huge technological evolution since 1984. So much so that  30 years later the average wiring harnesses has become extremely complex because the number of terminals have progressively increased from a typical 200 terminals in a 1994 vehicle to as many as 1,400 terminals, if not more in the very latest models. It therefore stands to reason that with so many terminals or connections, each and everyone of them are subject to corrosion, high resistive contact, poor contact, intermittent and implausible contact  and at times no contact.  The amount of copper wire used in older cars have also decreased substantially, from as much as 4 kilometers in length to about 1 kilometer. That's equates to a 75% saving on the wiring harness.  However with all the new technology and control modules and data buses, the cost of the wiring harness  cost equates to a quarter of the cost of the entire car. 

VW Polo Wiring Harness

As can be see in the image below, another VAG car sucummbed to hi-technology and desperately needs the service centre because it went into "Limp Mode".  It's most likely an electrical fault has caused this but that's just speculation on my part. However, since more than 50% of all warranty repairs are caused by electrical malfunctions, and approximately 30 percent of all tow-ins, are due to problems associated with the wiring harness, it can be therefore be said that 80% of all troubles experienced by car owners today are due to electrical faults.  Can we then also say that these fault are constantly recurring  because the manufacturer has overlooked the fact that 1400 contacts will invariably be influenced by  bumpy roads, shaking and hoping and flexing, subject to moisture and heat and dust and dirt? Desktop computers also have several hundred contacts but the difference between household computers and cars is that computers stay in a fixed place and doesn't get knocked about and shake on bumpy roads nor subjected to extreme heat and cold and moisture. Wouldnt it be fair to say that any car with electrical problems caused by the wiring harness should be repaired by the manufacturer under warranty and if not, these cars should be recalled. Anyway,  here is the Audi scan for your perusal.

Audi on a roll back with immobilizer issues

Chassis Type: 8E - Audi A4
Scan: 01 02 03 08 09 0F 11 15 16 17 18 36 37 45 46 55 56 57 65 67 69 75 76 77
-------------------------------------------------------------------------------

Address 01: Engine Labels:
Part No: 8E0 906 018 B
Component: 1.8L R4/5VT 0004
Coding: 11701
Shop #: WSC 14385

7 Faults Found
17978 - Engine Start Blocked by Immobilizer
P1570 - 35-10 - - Intermittent
17698 - Coolant Temp Sensor at Radiator Outlet (G83)
P1290 - 35-10 - Signal too Small - Intermittent
00527 - Intake Manifold Temperature Sensor (G72)
30-10 - Open or Short to Plus - Intermittent
17536 - Fuel Trim; Bank 1 (Mult)
P1128 - 35-00 - System too Lean
18058 - Powertrain Data Bus
P1650 - 35-10 - Missing Message from Instrument Cluster - Intermittent
18043 - Powertrain Data Bus
P1635 - 35-10 - Missing Message from A/C Controller - Intermittent
16712 - Knock Sensor 1 (G61)
P0328 - 35-10 - Signal too High - Intermittent
Readiness: N/A


Address 03: ----------------------------------------------------------------------
ABS Brakes
Part No: 8E0 614 517 A
Component: ABS/ESP allrad 1326
Coding: 04275
Shop #: WSC 60690

1 Fault Found
01317 - Control Module in Instrument Cluster (J285)
49-10 - No Communications - Intermittent


Address 08: ----------------------------------------------------------------------
Auto HVAC

Part No: 8E0 820 043
Component: A4 Klimaautomat 0711
Coding: 00000
Shop #: WSC 24576

4 Faults Found
01317 - Control Module in Instrument Cluster (J285)
49-10 - No Communications - Intermittent
00716 - Air recirculation Flap Positioning Motor (V113)
41-00 - Blocked or No Voltage
00474 - Control Module for Immobilizer
49-00 - No Communications
00474 - Control Module for Immobilizer
27-10 - Implausible Signal - Intermittent


Address 09: ----------------------------------------------------------------------
Cent. Elect.
Part No: 8E0 907 279 A
Component: int. Lastmodul RDW 1010
Coding: 00011
Shop #: WSC 63351

4 Faults Found
01317 - Control Module in Instrument Cluster (J285)
49-10 - No Communications - Intermittent
00474 - Control Module for Immobilizer
49-00 - No Communications
01317 - Control Module in Instrument Cluster (J285)
79-10 - Please Check Fault Codes - Intermittent
01312 - Powertrain Data Bus
49-10 - No Communications - Intermittent


Address 15: ----------------------------------------------------------------------
Airbags
Part No: 8E0 959 655
Component: Airbag 8.4E 3001
Coding: 0011702
Shop #: WSC 63351 000 00000

No fault code found.


Address 16: ----------------------------------------------------------------------
Steering wheel

Part No: 8E0 953 549 F
Component: Lenks?lenmodul 0304
Coding: 00001
Shop #: WSC 63351


2 Faults Found
00474 - Control Module for Immobilizer
49-00 - No Communications
01317 - Control Module in Instrument Cluster (J285)
49-10 - No Communications - Intermittent


Address 17: ----------------------------------------------------------------------
Instruments
Part No: 8E0 920 900 HX
Component: KOMBI+WEGFAHRS. RB4 D27
Coding: 00142
Shop #: WSC 19411

2 Faults Found
01176 - Key
07-10 - Signal too Low - Intermittent
65535 - Internal Control Module Memory Error
00-00 - -


Address 45: ----------------------------------------------------------------------
Inter. Monitor

Part No: 8E0 951 177
Component: Innenraumueberw. 0504
Coding: 00001
Shop #: WSC 00000

No fault code found.

Audi on a rollback on the way to the clinic.

So by the looks of it, with so many error codes,  it does seem like the wiring harness could be faulty because the control module lost communications with the Instrument cluster and when this happened the checksum no longer tallied, so the immobilizer inhibited starting. But considering that the key signal was low or intermittent, it could even be that the CR1220 lithium battery in the key fob died hence could not deactivate the immobilizer. It's just so scary that your relatively new and supposedly reliable VAG vehicle could act up at any time on a lonely road and leave your stranded, so make sure you have a tow-inn agent on speed dial.


Feel free to upload your VW, SKODA, SEAT & AUDI scans.

INTERMITTENT IMPLAUSIBLE

VW POLO 9N HIGHLINE

The VW Polo comes in three flavours viz. the 9N1, 9N2 and the 9N3, dating from 2002-2009.  The Skoda Fabia and the Seat Ibiza/Cordoba share many of the 9N trates but omit Address 25 since all their onboard control module functions are not identical. In the case of the VW Polo, it shares the coding in Address 17 with Address 25 because they are linked, but this applies morso to the 9N3. However, the easiest way to recognised the 9N and its clones, are by the 6Q0, 6Q1, 6L0, 6N0 and 6R0 modules which are also populated in the Polo 6N range. The interesting thing is that even though some module are the same in both its hardware and software, they have different codings specified. 

It is understandable, since the coding value is subject to the collective components fitted because the coding is a sum of the binary value applicable to the individual components. This can be seen in the three scans below. Be that as it may, module coding seems to be a huge problem with most vehicle owners who do their own repairs, however I have also seen qualified mechanicians struggle for days to get a car back to its readiness state. The status chart below is what every VAG driver / owner desires from their vehicle, but  is often totally elusive.

01-Engine -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: OK 0000
15-Airbags -- Status: OK 0000
17-Instruments -- Status: Status: OK 0000
19-CAN Gateway -- Status: Status: OK 0000
25-Immobilizer -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
56-Radio -- Status: OK 0000

Readiness: 0 0 0 0 0  / Gata de funcþie: 0 0 0 0 0 / Tests passés: 0 0 0 0 0

VCDS FAILED READINESS SETTING

What I have found, is that when a component that contributes to the module coding value malfunctions, the scan reads "1 Fault Found: 01044 - Control Module Incorrectly Coded" but if the malfunctioning component is first repaired or replaced, and the fault is cleared, the  01044 code does not return since the checksum of the module is once again correct. Many vehicles owners see this 01044 code and start changing module codes, normally just to see what happens. But, and a big but at that, before I continue, I need to stress that it's imperative to print out a scan of the faults and the module codings before any repairs are attempted, so that, if there is a problem, you can always revert back to the original coding. Failure to so could incapacitate your car until it can be correctly re-coded which could be both time consuming and expensive. Implausible and Intermittent (implausible  intermittent signal) problems on VAG cars are rife or rather intermittent and implausible  (implausible  intermittent signal)  problems on all cars are rife ever since control modules were introduced. The main reason for this is bad, poor or intermittent electrical contact, especially  considering the vast increased in the number of multi-pin plugs and sockets and edge connectors. Because vehicles move,  the  forces on the electrical connections constantly changes and that's besides the expansions caused by heat and the contractions caused by cold, and the corrosive effect of the weather on vehicles. Hence intermittent problems in all languages abound. What follows is just a sampling of the intermittent and implausible (implausible  intermittent signal) error codes we could encounter.

01314 - Engine Control Module
013 - Check DTC Memory - Intermittent

00816 - Sensor für Lenkhilfe
30-00 - Unterbrechung / Kurzschluß nach Plus

00716 - Air recirculation Flap Positioning Motor (V113)
000 -  -  - Intermittent

01336 - Bus de données Groupe Confort
80-00 - en mode fil unique

004506 - Fuel Pressure Sensor (G247)
P119A - 000 - Malfunction - Intermittent - MIL ON

01596 - Servomoteur de volet d´air frais/air recyclé (V154)
30-10 - Rupture/court-circuit au pôle + - Intermittent

01336 - Data Bus for Comfort System
80-10 - Single-Wire Operation - Intermittent

01271 - Stellmotor für Temperaturklappe (V68)
000 - - - Sporadisch

00588 - Airbag Igniter; Driver Side (N95)
32-10 - Resistance too High - Intermittent

00778 - Steering Angle Sensor (G85)
49-10 - No Communications - Intermittent

00706 - Relais de ventilateur de radiateur V7 et V35 -vitesse 2 (J513)
009 - Rupture/court-circuit à la masse - Intermittent

00896 - Closing unit tailgate (F256)
27-10 - Implausible Signal - Intermittent (implausible  intermittent signal) ----------

00576 - Klemme 15
002 - unterer Grenzwert unterschritten - Sporadisch

01312 - Powertrain Data Bus
37-10 - Faulty - Intermittent

00-Senzor unghi volan -- Status: OK 0000
01-Motor -- Status: Malfuncþie 0010
03-ABS frâne -- Status: OK 0000
08-Clima automatã -- Status: OK 0000
09-Electronica centralã -- Status: Malfuncþie 0010
15-Airbaguri -- Status: OK 0000
16-Electronicã volan -- Status: OK 0000
17-Instrumente bord -- Status: OK 0000
19-Poarta CAN  -- Status: Malfuncþie 0010
25-Blocare pornire -- Status: OK 0000
42-Uºa electr. ºofer -- Status: OK 0000
44-Asistenþã direcþie -- Status: OK 0000
46-Confort -- Status: Malfuncþie 0010
52-Uºa electr.pasager -- Status: Malfuncþie 0010
56-Radio -- Status: OK 0000
69-Tractare -- Status: Neautorizat 0001
76-Asistenþã parcare -- Status: OK 0000
7D-Încãlz. Aux. -- Status: Malfuncþie 0010

VW JETTA WIRING HARNESS

However,  we all desire the following messages from our cars:-  Aucun code défaut trouvé. No fault code found. Kein(e) Fehlercode(s) gefunden. Nu a gãsit coduri.  The wiring harness of all cars are made with flexible multicore wire with terminal connectors and clip-lock plugs to facilitate connection durability when driving on bumpy roads and uneven surfaces but it seems that shaking, vibration, heat, shafting and corrosion are responsible for the above errors which would probably not resulted if there were not as many interconnected sub harnesses, and multi-pin electrical connections. Volkswagen  vehicles wiring harnesses have undergone a huge technological evolution since 1984. So much so that  30 years later the average wiring harnesses has become extremely complex because the number of terminals have progressively increased from a typical 200 terminals in a 1994 vehicle to as many as 1,400 terminals in the latest models.

The cost implications of these new wiring harnesses and electronic modules constitute more than a quarter of the price of the cars. It is estimated that it takes approximately one and a quarter hours to completely assemble and engine on a production line, whereas it takes more than 5 hours to assemble a wiring harness. Since the complexity of wiring harnesses  escalated exponentially, it is only obvious that the time and cost associated with repairing wiring harness would increase considerably. Thinner wires are used carrying extremely low-level signals and data, interlinked electronic control modules, sensors and actuators communicating in several protocols, collectively resulting in limited access and mass confusion. Restated, automotive repairs have become lot more complicated and it is estimated that almost half of all warranty repairs are caused by electrical malfunctions, and approximately 30 percent of all tow-ins, are due to problems associated with the wiring harness.

This emphatically tells us that the wiring harness is no longer a collection of wires and connectors bound together, because each and every length of wire, connection,  twist and turn, is carefully engineered to suit the application and its environment. Therefore whenever electrical harness repairs become necessary, don't use shortcuts and offcuts pieces of wire from an old extension lead or solid wire from domestic electrical cable and solder joints. Solder joints will eventually break due to vibration and spirited driving. Use the appropriate motor grade multicore flexible wiring of the appropriate diameter with the correct terminals and the appropriate electronic modules and components to restore the wiring harness to its original integrity because failure to do so, will only result in more intermittent and implausible (implausible  intermittent signal) contacts. To give you some idea of the wiring harness complexity I have included the numbers of the various sub harnesses that constitute the entire harness for my car.

WIRING HARNESS

VW Polo Highline 2.0L wiring harness  numbers ( Teilenummern ZSB- Leitungsstrang)

6Q2 970 005 DH, 6Q2 970 006 Q, 6Q2 970 010 L,  6Q2 970 024 H,
6Q2 970 076 AB, 6Q2 970 091 H, 6Q2 970 099 E , 6Q2 970 106 RB,
6Q2 970 111 D,   6Q2 970 154 C, 6Q2 970 191 D,  6Q2 970 083 CJ,
6Q2 970 050 P,    6Q2 970 125 K, 6Q2 970 102 RQ,  6Q2 970 023 CD,
6Q2 970 003 L,    6Q2 970 049 F, 6Q2 970 000 RQ,   6Q2970 030 AA
6Q2970 012 CN,

The underlined 6Q2 970 049 F above is the Cent. Elect. Controller 0009 BN-SG.   2S36 siting at Address 09,  the rest are individual harnesses or rather interconnecting parts of a whole harness.

SCANS

Chassis Type: 9N1 - VW Polo
Scan: 01,02,03,08,09,15,17,19,37,44,46,56,69

Address 01 -------------------------------------------------------
Controller: 032 906 032 E
Component: ME7.5.10 *2503
Coding: 00071

Address 03 -------------------------------------------------------
Controller: 6Q0 907 379 AF
Component: ABS 8.0 front H03 0002
Coding: 0002175

Address 08 -------------------------------------------------------
Controller: 6Q0 820 045
Component: Klimaanlage X0840

Address 09 -------------------------------------------------------
Controller: 6Q0 937 049 D
Component: À0_0 BN-SG. 1S34
Coding: 25742

Address 15: ------------------------------------------------------
Airbags
Controller: 6Q0 909 605 AE
Component: 0H AIRBAG VW5 0C 0010
Coding: 12360

Address 17 -------------------------------------------------------
Controller: 6Q0 920 823 B
Component: KOMBI+WEGFAHRSP VDO V02
Coding: 00141

Address 19 -------------------------------------------------------
Controller: 6N0 909 901
Component: 0000 GATEWAY CAN 1S34
Coding: 00014

Address 44 -------------------------------------------------------
Controller: 6Q0 423 156 AB
Component: LenkhilfeTRW V270
Coding: 10140

Address 46 -------------------------------------------------------
Controller: 6Q0 959 433 E
Component: 67 Komfortgerát 0002
Coding: 00018

Address 56 -------------------------------------------------------
Controller: 6Q0 035 186 A
Component: Radio FF6 0001
Coding: 00401

End -------------------------------------------------------


Fahrzeugtyp: 9N - VW Polo
Scan: 01 02 03 08 09 15 17 19 25 37 44 45 46 56 76

Adresse 01: -------------------------------------------------------
   Motor
   Teilenummer: 03D 906 023
   Bauteil: SIMOS91 1.2l 2V     5415
   Revision: --H04---    Seriennummer: VWZ5Z0G8041219
   Codierung: 0000071
   Betriebsnr.: WSC 00810 219 84798
 
Adresse 03: -------------------------------------------------------
   Bremsen  
   Teilenummer SW: 6Q0 907 379 AF    HW: 6Q0 907 379 AF
   Bauteil: ABS 8.0 front   H05 0002
   Revision: 00000000    Seriennummer: 00000000000000
   Codierung: 0002082
   Betriebsnr.: WSC 00788 785 00200

Adresse 08: -------------------------------------------------------
   Klima/Heizung  
   Teilenummer: 6Q0 820 045
   Bauteil: Klimaanlage        X0850

Adresse 09: -------------------------------------------------------
   Bordnetz      
   Teilenummer: 6Q1 937 049 F
   Bauteil: 0009 BN-SG.         2S36
   Codierung: 25742
   Betriebsnr.: WSC 00788
 
Adresse 15:  -------------------------------------------------------
   Airbag      
   Teilenummer: 1C0 909 605 K
   Bauteil: 19 AIRBAG VW51 0P   0010
   Codierung: 12601
   Betriebsnr.: WSC 00788
 
Adresse 17: -------------------------------------------------------
   Kombiinstrument    
   Teilenummer: 6Q0 920 804
   Bauteil: KOMBIINSTRUMENT AGD V04
   Codierung: 01131
   Betriebsnr.: WSC 00000
 
Adresse 19: -------------------------------------------------------
   CAN-Gateway      
   Teilenummer: 6N0 909 901
   Bauteil: 01K1 GATEWAY CAN    2S36
   Codierung: 00014
   Betriebsnr.: WSC 00788
 
Adresse 25: -------------------------------------------------------
   Wegfahrsperre
   Teilenummer: 6Q0 920 804
   Bauteil: IMMOBILIZER     AGD V04
   Codierung: 01131
   Betriebsnr.: WSC 00000
 
Adresse 44: -------------------------------------------------------
   Lenkhilfe    
   Teilenummer: 6Q0 423 156 AB
   Bauteil: LenkhilfeTRW        V270
   Codierung: 10140
   Betriebsnr.: WSC 00788
 
Adresse 46: -------------------------------------------------------
   Komfortsystem    
   Teilenummer: 6Q0 959 433 E
   Bauteil: 3F Komfortgerát     0002
   Codierung: 00019
   Betriebsnr.: WSC 00788
 
Adresse 56: -------------------------------------------------------
   Radio      
   Teilenummer SW: 6Q0 035 152 G    HW: 6Q0 035 152 G
   Bauteil: Radio DE2           0007
   Revision: 00005000    Seriennummer: VWZ4Z4G3272350
   Codierung: 0020200
   Betriebsnr.: WSC 00788 785 00200
 
Ende -------------------------------------------------------

Type chassis: VW Polo 9N
Scanner: 01 02 03 08 09 15 17 19 37 44 45 46 56 76

Adresse 01: -------------------------------------------------------
Moteur
No. pièce: 038 906 019 NC
Pièce: 1,9l R4 EDC 0000SG 6138
Codage: 00002

Adresse 03: -------------------------------------------------------
Freins ABS
No. pièce Log: 6Q0 907 379 AF Mat: 6Q0 907 379 AF
Pièce: ABS 8.0 front H05 0002
Révision: 00000000 No. de série: 00000000000000
Codage: 0002193

Adresse 08: -------------------------------------------------------
Climatronic
No. pièce: 6Q0 907 044 E
Pièce: CLIMAtronic PQ24 3805

Adresse 09: -------------------------------------------------------
Centrale Elec.
No. pièce: 6Q1 937 049 F
Pièce: 0009 BN-SG. 2S36
Codage: 09870

Adresse 15: -------------------------------------------------------
Airbags
No. pièce: 1C0 909 605 K
Pièce: 17 AIRBAG VW51 0N 0010
Codage: 12599

Adresse 17: -------------------------------------------------------
Instruments
No. pièce: 6Q0 920 825 H
Pièce: KOMBIINSTRUMENT VDO V06
Codage: 01141

Adresse 19: -------------------------------------------------------
Gateway CAN
No. pièce: 6N0 909 901
Pièce: 01K1 GATEWAY CAN 2S36
Codage: 00014

Adresse 44: -------------------------------------------------------
Direction assistée
No. pièce: 6R0 423 156
Pièce: LenkhilfeTRW V272
Codage: 10120

Adresse 46: -------------------------------------------------------
Module confort
No. pièce: 6Q0 959 433 E
Pièce: 5F Komfortgerát 0002
Codage: 00017

Adresse 56: -------------------------------------------------------
Radio
No. pièce Log: 6Q0 035 152 E Mat: 6Q0 035 152 E
Pièce: Radio 9NK 0004
Révision: 00001000 No. de série: VWZ4Z4H0100621
Codage: 0040400

End -------------------------------------------------------

Feel free to upload your VW, SKODA, SEAT & AUDI scans.

Adresse, Address,  Betriebsnummer, WS Code, Control Module for Airbags, Control Module for Climatronic, Control Module in Instrument Cluster, Power Steering Control Module, Engine Control Module, Data Bus for Comfort System, Coding, Control Module for Digital Sound Package, No Signal/Communication - Intermittent, Intermittent Operation, Defective - Intermittent, Open Circuit — Intermittent, Short to Ground — Intermittent, Open or Short to Plus — Intermittent, Implausible Signal — Intermittent, No Communications - Intermittent, Electrical Fault in Circuit - Intermittent,

01044 - CONTROL MODULE INCORRECTLY CODED

CONTROL MODULE INCORRECTLY CODED

Since 1994 auto repairs has drastically changed, so much so that most cars cannot be repaired  without a diagnostic code tester. It is therefore advantages to invest in one of the hand held free standing devices or cable interfaces that plugs into a USB port of a laptop computer running the appropriate software to do the necessary. The best software to date for Vag cars is undoubtedly VCDS from Ross Tech. Their latest version is version 14. The software is absolutely free but the interface cable comes at a cost. It is a bit pricy but its a worthwhile investment since it entitles you to free updates for life. This interface cable has a built in PAL chip which doubles-up as a dongle containing the cable activation code. Even though there are several out-band 3rd party interface cables available on the market, none of them gives you the confidence that a VCDS HEX-CAN automotive diagnostic device, that is backed by a service company ready to help with any automotive queries, gives you. Bare in mind that this software has the ability to change the behaviour of the electronic control systems built into your car which can result resulting in catastrophic effects if not performed correctly. If you lack the competence or confidence to perform these operations, or even if you are unfamiliar with or the software, I urge you to refrain from changing anything and obtain an experts advice or assistance. Write down or print out all codes and settings so that it is easy to revert back to them.

Below are just a few of the faults that have popped-up on various vag cars over the past few years. Since the codes cover all Vag cars, the code "01044 - Control Module Incorrectly Coded" has occurred several thousand times in all makes and models of Vag cars, in all languages and countries throughout the world.

01044 - CONTROL MODULE INCORRECTLY CODED

01044 - Modul de comanda: codare incorecta
        35-00 -  -

01044 - Steuergerät falsch codiert
        35-00 -  -

01044 - Módulo de control codificadas incorrectamente
        35-00 -  -

01044 - Modul za kontrol Nepravilno Kodiran
        35-00 -  -

01044 - module de commande codées correctement
        35-00 -  -

01044 - Control Module ongecodeerde
        35-00 -  -

01044 - Beheer Module Verkeerd Gekodeerde
        35-00 -  -

01044 - Upravljački modul Pogrešno Coded
        35-00 -  -

01044 - Control Module Nepareizi Coded
        35-00 -  -

01044 - 控制模塊編碼不正確
        35-00 -  -

01044 - Kòngzhì mókuài biānmǎ bù zhèngquè
        35-00 -  -

01044 - Modul de control codificate incorect
        35-00 -  -

01044 - Kontrolli Module kodifikua Gabimisht
        35-00 -  -

01044 - وحدة التحكم الأكواد بشكل غير صحيح
        35-00 -  -

01044 - Řídicí modul nesprávný kód
        35-00 -  -

01044 - Modul Kawalan Salah Dikodkan
        35-00 -  -

01044 - Kontrol Modülü hatalı Kodlu
        35-00 -  -

01044 - Control Module Felaktigt Kodad
        35-00 -  -

Genuine VCDS cable and Software from Ross Tech.

What I find most intriguing is that for most DTC codes, VW offers some sort of help by using words like "intermittent" " implausible" "short circuit" "limit exceeded", etc.. like these faults below, but the 01044 faulty code featured above offers absolutely none. However, I have included some data below that may be of some help. Should you find these codes helpful, all I ask is for you to like my site on G+1 , Facebook, Twitter, Pinterest, etc.

00532 - Supply Voltage B+
07-10 - Signal too Low - Intermittent

01044 - Control Module Incorrectly Coded
35-00 -  -

01179 - Incorrect Key Programming
35-00 - -

01179 - Incorrect Key Programming
005 - No or Incorrect Basic Setting / Adaptation

00852 - Loudspeaker(s); Front
44-00 - Short Circuit

16795 - Secondary Air Injection System: Incorrect Flow Detected
P0411 - 35-00 -  -

01044 - Control Module Incorrectly Coded
35-00 - -

00933 - Electric Window Motor; Passenger Side (V148)
62-10 - No or Incorrect Adjustment - Intermittent

16795 - Secondary Air Injection System: Incorrect Flow Detected
P0411 - 002 - Lower Limit Exceeded

16825 - EVAP Emission Control Sys
P0441 - 35-10 - Incorrect Flow - Intermittent

00928 - Locking Module for Central Locking: Front Driver Side (F220)
27-00 - Implausible Signal

VW 9N CODES FOR:
CONTROL MODULE INCORRECTLY CODED

If  one of the following controllers is fitted in your car, try each of these codes individually  and you are guaranteed to solve your " Control Module incorrectly coded" problem, providing you have just changes the coding of one module or replaced only one module.  I need to stress as I have in a previous blog that every Control module that is fitted in your car has a prefered coding which is subject to the equipment it supervises. As such, its coding is stored as an onboard binary number, which in essence is the binary sum of the features for that specific module. Whereas the master ECU / Ctrl Head Dash  also stores an onboard binary number which in essence is the binary sum of all the Control Module's coding fitted in the car. This binary sum is called the checksum and any incorrectly coded  module will result in an erroneous checksum. If this is the case, the erroneous checksum is compared to a reference checksum also stored in the ECU module and any discrepancy could incapacitate your Volkswagen completely or present you with some peculiarities and error codes to match. Like the notorious 01044 control module incorrectly coded error. Checksum verification was adopted by BOSCH Motronic ECUs to validate its EPROM's stored data. So, it is wise not to change the coding or replace any control modules in your VW AUDI, SKODA or SEAT unless you are au fait with binary and hexadecimal number systems.

Address 09: Cent. Elect. [21343 login]
Component: 0009 BN-SG. 2S36

Controller: 6Q1 937 049 F
Coding: = 09870 / 09390 / 08332 / 25742 / 26030 /
26254 / 00004 / 09358 / 16396 / 08588 / 08204 /
00004 / 09646 / 24716 / 25743 / 24588 / 17422 /

Controller: 6Q1 937 049 D
Coding: = 00140 / 16524 / 09406 / 17422 / 25610 /
25614 / 25774 / 09358 / 25646 / 00012 / 01166 /
25774 / 25742 / 09870 / 09390 / 09646 /

Controller: 6Q1 937 049 C
Coding: = 09358 / 09390 / 00140 / 16396 / 25742 /
00012 / 25742 / 26046 / 25614 /

Controller: 6Q1 937 049 B
Coding: = 25754 / 09374 / 00140 / 17594 / 25758 /

Controller: 6Q1 937 049
Coding: = 00141 / 09234 / 09870 / 09362 / 09358 / 09394 / 09646 /

Address 09:  Cent. Elect.  [21343 login]
Component: 0000 BN-SG. 2S36
Address 09: Controller: 6Q1 937 049 F Coding: 09358
Address 09: Controller: 6Q1 937 049 F Coding: 25742
Address 09: Controller: 6Q1 937 049 F Coding: 25743

Address 09:  Cent. Elect.  [21343 login]
Component:  000B BN-SG. 2S36
Address 09: Controller: 6Q1 937 049 F Coding: 08588
Address 09: Controller: 6Q1 937 049 F Coding: 16524
Address 09: Controller: 6Q1 937 049 F Coding: 24716

NB! More component codes in the next blog ...

INSTRUMENT CLUSTER / IMMOBILIZER / KOMBI
6Q0 920 825

Component: KOMBIINSTRUMENT VDO V06
Address 17: Instruments Controller: 6Q0 920 825 E Coding: 01144

Component:  INSTRUMENT CLUSTER VDO V07
Address 17: Instruments Controller: 6Q0 920 825 E Coding: 01144

Component: KOMBIINSTRUMENT AGD V05
Address 17: Instruments Controller: 6Q0 920 825 F Coding: 01132

Component: KOMBIINSTRUMENT AGD V02
Address 17: Instruments Controller: 6Q0 920 825 F Coding: 01132

Component: KOMBIINSTRUMENT AGD V04
Address 17: Instruments Controller: 6Q0 920 825 F Coding: 01132

Component:  KOMBIINSTRUMENT VDO V06
Address 17: Instruments Controller: 6Q0 920 825 F Coding: 01132

Component: KOMBIINSTRUMENT VDO V03
Address 17: Instruments Controller: 6Q0 920 825 G Coding: 01132

Component: KOMBIINSTRUMENT VDO V06
Address 17: Instruments Controller: 6Q0 920 825 G Coding: 01132

COMPONENT KOMBIINSTRUMENT VDO V06
Address 17: Instruments Controller: 6Q0 920 825 H Coding: 01141

Component: KOMBIINSTRUMENT VDO V06
Address 17:  Instruments Controller: 6Q0 920 825 J Coding: 01142

Component: KOMBIINSTRUMENT VDO V05
Address 17:  Instruments Controller: 6Q0 920 825 K Coding: 01148

Component:  KOMBIINSTRUMENT VDO V02
Address 17:  Instruments Controller: 6Q0 920 825 L Coding: 01148

CENTRAL CONVENIENCE

Address 46:
Controller:Central Conv.

06 Komfortgerát 0002 6Q0 959 433 C Coding: 00067
07 Komfortgerát 0002 6Q0 959 433 C Coding: 00259

63 Komfortgerát 0002 6Q0 959 433 E Coding: 00016
3  Komfortgerát 0002 6Q0 959 433 E Coding: 00016
5F Komfortgerát 0002 6Q0 959 433 E Coding: 00017
   Komfortgerát 0002 6Q0 959 433 E Coding: 00018
63 Komfortgerát 0002 6Q0 959 433 E Coding: 00016
64 Komfortgerát 0002 6Q0 959 433 E Coding: 00019
65 Komfortgerát 0002 6Q0 959 433 E Coding: 00018
67 Komfortgerát 0002 6Q0 959 433 E Coding: 00018
3F Komfortgerát 0002 6Q0 959 433 E Coding: 00018
3F Komfortgerát 0002 6Q0 959 433 E Coding: 00019
2F Komfortgerát 0002 6Q0 959 433 E Coding: 00064
4y Komfortgerát 0002 6Q0 959 433 E Coding: 00065
4z Komfortgerát 0002 6Q0 959 433 E Coding: 00065
6K Komfortgerát 0002 6Q0 959 433 E Coding: 00065
4U Komfortgerát 0002 6Q0 959 433 E Coding: 00066
4M Komfortgerát 0002 6Q0 959 433 E Coding: 00064
31 Komfortgerát 0002 6Q0 959 433 E Coding: 00067
4T Komfortgerát 0002 6Q0 959 433 E Coding: 00258

   Komfortgerát 0002 6Q0 959 433 F Coding: 00018
   Komfortgerát 0002 6Q0 959 433 Coding: 00021

J2 Komfortgerát 0002 6Q0 959 433 G Coding: 00064
20 Komfortgerát 0002 6Q0 959 433 G Coding: 00065
41 Komfortgerát 0002 6Q0 959 433 G Coding: 00017

1N Komfortgerát 0002 6Q0 959 433 H Coding: 00018
2Y Komfortgerát 0002 6Q0 959 433 H Coding: 00018
1N Komfortgerát 0002 6Q0 959 433 H Coding: 00019  
1R Komfortgerát 0002 6Q0 959 433 H Coding: 00067
0H Komfortgerát 0002 6Q0 959 433 H Coding: 00067

CONTROL ARM RUBBERS

VW POLO CONTROL ARM & TIE-RODS

A couple of weeks ago to my surprise,  I discovered that my car's front tyres were running  smooth on the inside.  It was that bad that I needed to replace them but somehow I never noticed until from a distance, I saw something white stuck to the right side front tyres. I was thinking it may be a sticky sweet wrapper that got stuck to the thread, so I went to remove it. That’s when I saw it was a patch of shining wire protruding through the rubber. I was dismayed. The outer edge up to the middle of the tyre had perfect thread, at least 4mm or more but the inside was bald as an egg. 

My VW Polo getting the full treatment.

Thats where the control arm rubbers sits, 

There was no way I was going to fit brand new tyres and allow the same to happen to them. I suspected that the alignment went awry so I drove my car in that condition to determine whether I was right or wrong. I released the steering on a straight road a few times and every time the car veered to the left, towards the pavement. Convinced that it was alignment, I fitted my spare wheel and took my VW Polo Highline for wheel alignment to get it sorted before replacing the tyres.

New VW control arm rubbers / cleaned-up VW control arms

Busted rubber boots on both and left tie-rod ends, due for replacement.

 After waiting for more than an hour at the wheel alignment centre, it was eventually my turn to get service. My car was hoisted about hip high on the lift. The technicians then jacked-up the front wheels placed metal pad of sorts under each of the front wheels which was part of the wheel alignment sensor equipment that they later fitted to all four wheels. They then centred the steering wheel, locked it in place with a mechanical device and fired up the diagnostic computer/programme to check my car's wheel alignment. A good 15 minutes later they discovered that their version of the diagnostic software did not have the settings for a VW Polo 2.0 litre Highline. In fact there wasn't even a 2.0 litre Polo category listed.

Front and back view of new tie-rod ends.

There is absolutely no difference between the original ans pirate part other than the VW logo

The technician scrolled through the entire list a couple of times before he gave up and told me that they are stuck without the correct setting and therefore cannot do the alignment. I asked, what about trying the software for one of the other VW Polo models. Considering all the Polo's are the same shape and size and that it’s only the engine capacity that vary, perhaps it may work.  So he tried the 1.8 litre setting which showed my Polo's alignment was perfect and that there was no error. He then tried the 1.6 and the 1.9TDi software, both with the same results -no problem. I protested “How can that be? Look at my front tyres! Now that the car's tyres were eye-level the left tyre was almost just as bad as the right one. The technicians agreed that there is a problem and started speculating that if both my swing arm rubbers were uniformly perished the alignment would  technically still be in but the car would veer off the road and the tyres would run bald on either the inner or outer edge. They lifted the car higher and pushed a tyre lever into the control arm rubbers and convincingly said the one side is definitely broken.  Thank you very much and off I went.

Left image shows left Control arm Rubber, Right image shows right side.

Left and Right Control Arm Rubbers

Back at the VW service agents, 2 x control arm rubbers please. Yes, we have stock, R1200 (+/-$120) please. What! For two pieces of rubber? But since I needed it, I paid. Back home I jacked-up the car, placed it on car stands and stripped the front suspension until I removed said rubbers. By the way, I found the boots on tie-rod ends torn so back to the agents I went. "Sorry out of stock, expecting stock to arrive in 40 days". This was unacceptable so off to the local motor spares I went in search of tie-rod ends. I found them sold together with the control arm rubbers at R180 each, tie-rod ends R120 each. Everything together cost me R600 ($60), exactly half of what I already spent on rubbers alone. So after I fitted them to my Polo, I returned the Control arm rubbers to the VW agents for a full refund.  Amazingly the car now drives normal, no veering to the left or right and the alignment centre still says my alignment is normal, even though they or none of the other service centres they phoned have the software alignment settings for my 2.0L Polo highline. I now realise that she's an oddball.

EPC DEMYSTIFIED CONTINUED 2

Continued from EPC DEMYSTIFIED CONTINUED 1.

  ...  I only became aware of this when my EPC light went on due to the knock sensor. See picture blog.  More...

 PART 3

BREAKING THE CODE

What needs to be mentioned as a basis of understanding, is that OBD (on-Board Diagnostics) was introduced in the 70's along with CDI (capacitive discharge ignition systems) as DIY kits. Few cars had fuel injectors, points and coils were fast being taken over by electronic modules. During this time some standards were introduced but they were not very well defined and as such manufacturers developed their own and applied their specific systems and developed their own code descriptions which later became known as OBD1. This was considered undesirable and counterproductive since none franchised service, and general mechanical repair centers had to purchase different scan tools, interface cables and connectors, skills and manuals for each make and model of car they specialized in. This resulted in vehicle diagnostics becoming unwieldy expensive. In February of 1986, Robert Bosch founder of Bosch, introduced the CAN (Controller Area Network) serial bus system to  the Society of Automotive  Engineers (SAE) in motor town of Detroit.

This influenced the  Society of Automotive  Engineers (SAE) who subsequently drafted a list of standards and practices that aught to be implemented by all automobile  manufacturers and recommended them to the Environmental Protection Agency (EPA). The EPA weighed-up these standards and recommendations, acknowledged their benefits, and adopted them. The standards criteria included a precisely defined diagnostic connector for each auto manufacturer, a standard scan tool and a common electrical communications protocol and a common data format, and the ability to monitor other
vehicle parameters. Lastly that the standard scan tool should interface with vehicles of all manufacturer. It also included mandatory definitions and descriptions for certain emission control system  defects which was labeled the ‘P0’ Codes. Manufacturers were allowed to generate and use their own ‘manufacturer specific code descriptions’ known as ‘P1’ Codes. This collaboration of standards became known as OBDII, (OBD2) and was adopted for implementation by January of 1996. Two types of scanner codes, namely manufacturers codes like VAG codes and SEA Codes are now the standard practice.

OBD-II  

As mentioned above, Powertrain Control Module (PCM) error codes are assigned the prefix P and pertain to the, Engine management, Transmission management, Fuel Pump and Gasoline Management, Automatic Transmission – Hydraulic Control, Emission control system, evaporative emission purge control (HVAC), Auxiliary module management and other some 0n-board Hybrid application.  For example P1340  suggests that the Powertrain triggered a DTC and describes it as an "Crankshaft-/Camshaft Position Sensor Signals Out of Sequence"

From the above example it would thus be easy to interpret the DTC below relating to EPC (Electronic Power Control)

DTC (VAG)   DTC (SAE)  Society of Automotive  Engineers

16504 P0120 Throttle Position Sensor A - Circuit Malfunction
16505 P0121 Throttle Position Sensor A - Circuit - Performance Problem - Out of Range
16506 P0122 Throttle Position Sensor A Circuit - Low Voltage Input
16507 P0123 Throttle Position Sensor A Circuit - High Voltage Input
16894 P0510 Throttle Position Sensor - Closed Switch- idle micro-switches -F60 malfunctioning
17951 P1543 Throttle Actuation Potentiometer - Signal too Low
17952 P1544 Throttle Actuation Potentiometer - Signal too High
17913 P1505 Throttle idle micro-switches -F60 not/short-circuit opens
17914 P1506 Throttle idle micro-switches - Switch Does Not Open/Short to Ground
17988 P1580 Throttle Actuator (B1) Fault - May be caused by low battery if found with 16487 (P0103)

18038 P1630 Accelerator Pedal Position -G79 signal too small  (low)
18039 P1631 Accelerator Pedal Position -G79 signal too largely (high)
18040 P1632 Accelerator Pedal Position -G79 supply voltage malfunction
18041 P1633 Accelerator Pedal Position -G185 signal too small
18042 P1634 Accelerator Pedal Position -G185 signal too largely
18047 P1639 Accelerator Pedal Position 1+2 Range/Performance -G79 and -G185 implausible signal
18048 P1640 Internal Controller Module defective (EEPROM) Error

EPC Circuit.

The EPC  circuit consists of a number of disparate components that control and supervise, regulate and determine the throttle valve position at all times. They include;

1) the accelerator pedal position sender (TP sensor G69)
2) the accelerator pedal position sender -2, (G185)
3) Black 6-pin plug with 6-pin with Gold plated contacts

NB! The above three components are part of the accelerator pedal.

4) the throttle valve control module (unit),
5) the K132 EPC fault lamp, (electronic throttle control fault indicator)
6) the engine control module (unit).

Firstly we going to do a test on components 1, 2 and 3 above. To do this test, you need a Fluke multimeter or similar for a voltage and continuity / resistance test. Unplug the 6-pin plug from the accelerator pedal and switch on the ignition. Connect the multimeter and check for a 4.5 volt reading between;-

pin 1 and ground, then between pin 1 and pin 5
Pin 2 and ground, then between pin 2 and 3.
If tests prove to be "OK", switch ignition off.
Do additional checks for short circuits between one another and ground and if this checks "OK",

Locate the ECU, normally inside cowl. Disconnect the ECU from its socket, identify pins 34 & 34, 35 & 36, and 72 & 73 on the socket. Disconnect the 6-pin plug from the accelerator pedal once again and check for continuity between this plug and the ECU socket. There should be continuity between pins:-

1 of the 6-pin plug and pin 72 of the ECU socket.
2 of the 6-pin plug and pin 73 of the ECU socket.
3 of the 6-pin plug and pin 36 of the ECU socket.
4 of the 6-pin plug and pin 35 of the ECU socket.
5 of the 6-pin plug and pin 33 of the ECU socket.
6 of the 6-pin plug and pin 34 of the ECU socket.

Any resistance above 1.5ohms should be investigated for corrosion. This often causes the engine to surge (idle unevenly or rather breaths) However, if this test proves "OK" and no wiring malfunction is detected, replace G69 and G185 (single unit) on the accelerator pedal. NB! these components are non adjustable and needs to be replaced as a whole.

When the ignition is turned on, the ECU checks all EPC components necessary for the proper  functioning of the Electronic Power Control. If a malfunction is detected in the EPC (Electronic Power Control) system whilst the engine is running, the ECM will simultaneously activate the EPC (Electronic Power Control) warning light and make an entry of this malfunction in  the ECU (electronic Control unit) DTC (Diagnostic Trouble Codes non-volatile memory.  By a process of eliminate the EPC fault can be fixed.

The list below categorises VW and Audi manufacturer predetermined data groups which varies depending on the vehicle, year, engine, engine code and management system on board.

Group Number / Group Category

1–9     General engine activity data
10–19 Ignition data
20–29 Knock control data
30–39 02 sensor control system data
40–49 Three-way CAT data
50–59 Engine speed control data
60–69 Throttle drive data
70–79 Emissions reduction data
80–89 Special function data
90–97 Power increase data
98–100 Compatibility data
101–109 Fuel Ignition data
110–119 Boost pressure control data
120–129 Control unit communication data
130–150 Special info data

Based on the data from the above table EPC problems are associated with group 60-69. However, on Expert Systems Diagnostics Group 60, holds the EPC Adaptation data, group 61 holds EPC-system 1 data and group 62 holds the EPC system 2 data. Group 66 holds the speed-o-cruise data.

NB! If you found this information useful, please link to this page.

EPC DEMYSTIFIED CONTINUED 1

Continued from EPC DEMYSTIFIED.  

  ....But it’s not that simple. There is a lot more to it than meets the eye.....

 PART 2

But it’s not that simple. There is a lot more to it than meets the eye. Cars exclusively use embedded microcontrollers (µContollers) with embedded firmware in preference to microprocessors with loadable software. In order for a microprocessor to function properly in any device, it must contain dedicated internal circuitry and firmware specific to its function, have inputs and outputs and an oscillator circuit among other circuitry and an OS (Operating system). A DVR (Digital Video recorder), or a PVR (personal Video recorder) or a set-top-box or embedded network appliance or data router are just a few examples of such systems. µControllers  are less significant and less sophisticated than microprocessors, more dedicated to its specific need, often cheaper, faster, safer and smaller. Embedded µControllers are therefore the natural choice for car manufacturers. And there are several manufactures that produce µControllers families specifically for the motor trade.

So it should be understood that companies like Bosch, Digifant, Delco  and other engine management ECU manufacturers and electronic module manufacturers uses the same microcontroller chip families or similar microcontroller chip families, designed and manufactured for them by a selected few silicon chip manufacturers.  In the same vein, computer manufacturers like IBM, Dell, Sony, Toshiba and Lenovo, etc. all use microprocessors manufactured by Intel Corporation or AMD in their laptops and computers, whereas Apple uses microprocessors manufactured by Motorola.

Baring in mind, that much like Motorola, Intel Corporation and AMD produces different featured microprocessor chips with different instruction sets,  along with their auxiliary support chips for low-end and high-end computers; such as 4 bit, 8bit, 16bit, 8086 family of chips, 32bit Pentiums, I5, I7, 64bit, XEON, 128bit big Endian and small Endian microprocessors etc; so does Infineon, Altera, Freescale, Atmel and ARM etc, manufacture different featured microcontroller chips for both low-end cars and high-end cars which are specifically chosen for their internal features and software by the various ECU and electronic module manufacturers like  Bosch,  LUCAS, DENSO, Delco, DELPHI, FENIX, HITACHI, HELLA,  MARELLI, Siemens, etc. These microcontroller chip families can roughly be categorized into four sub sectors, those specific to Powertrain functions (P), those specific to the Body and Safety functions (B), those with specific functions for Chassis (C) and those specific to Internal Convenience & communication(U).

In a nutshell all the sub systems in your vehicle are controlled by these on-board computer chips, each at the heart of an electronic module flanked by associated components and sensors. Each of these modules are in fact a fully fledged computer in its own right, situated in various positions throughout the car and linked together by a wired networked called a network bus and all are accessible through the Databus diagnostic interface for adaptation.

When the ignition is switched on, several dashboard warning lamps light-up and stays lit for the duration of the internal test cycle (<30 seconds). Should all tests check OK, all lights goes however if all systems does not check out OK, the relevant light will stay on and a fault will be logged in memory . After the car is started, the ECU monitors all sensors  and continually takes readings from the complete range of powertrain modules and sensors. These readings are then compared with default readings stored in the operational logic of the  system. Should the sensor reading coincide and agree with the stored program value or values, the microcontroller will send the  required outputs to the relevant actuators, for example the injectors. If the sensor readings differ and are out of specification,   "not within the required limits",  it will take another and if this sensor reading continues to be ‘out of limits’ a DTC will be triggered and sent to non-volatile memory. Depending on the nature of the fault, the embedded program may or may not instruct the microcontroller to make internal changes, thus operate on different criteria until a repair is effected, or until the fault has been cleared.

So whenever a mechanical or electronic problem arises in either the Powertrain (P), the Body (B), the Chassis (C) or the internal Conveniences & Communication (U) areas, the relevant module or modules triggers the on-board self diagnostics program and generates a DTC (Diagnostic Trouble Code) which is then stored in the non-volatile memory of the ECU for later retrieval by mechanical technicians. At the point When a DTC code is logged in memory, the system self-diagnosis system also alerts the driver with a visible indication  of trouble by turning on a warning light on the dashboard like the "EPC light", or the "Malfunction Indicator Lamp" (MIL) which on European cars is known as the "Check Engine Light". This doesn't tell you  the nature of the problem, even though it could be something serious, or not. After the necessary repairs are completed, a diagnostic scan tool should be used to clear the DTC errors  and to turn the malfunction indicator light (MIL) or EPC light off. Thereafter the car should be taken on a short test dive to ascertain that the previous drive issue or issues are resolved. Then the car should be hooked up to the diagnostic scan tool once again in order  to confirms that the DTC or DTCs is also no longer present.

The nature of such mechanical problem may  prevent the engine from starting or it may idle erratically, switch off immediately after starting, refuse to rev higher than 1500 rpm and impede driveability (limp mode), difficult cold starting, misfire, lazy acceleration, high idling speed, fluctuating rev counter, excessive fuel consumption, difficult warm starting, excessive black smoke, poor engine response or emits blue/grey smoke,  etc ... Each of these faults and so many others each produce individualized codes.   In most cases it would be expedient to engage the services of a roll-back to get your car to a VW service center so that diagnostics can be run on the car.

With sufficient knowledge and an appropriate diagnostic apparatus (Autoboss, Pico Scope, Range, VCDS, AutoEnginuity,  ScanXLpro), code reader or scanner, plugged into the car's 16 pin diagnostic plug, mechanical minded persons can read these faults, print then or save them to an SD card or harddrive, send signals and communicate with the ECUs, read the measured values and interrogate the actuators. The DTC in memory however do not identify the part that has gone faulty but rather provides you  with a general idea to its area of origin. Often long before a DTC code is generated the fault may already have existed so when the you view the DTC it could show that the fault occurred twice of thrice or even six times before. The ECU software is designed to monitor the frequency of error and if it is an isolated occurrence the ECU clears the fault after a certain distance is traveled but that dependent on the severity of the fault. For arguement's sake lets say 300kms. If it happens once in 300kms it could automatically clears the fault but should it happen four times during the same distance a DTC will be registered, the car could go into limp mode since it may be unsafe to drive the car if it's a breaking or steering issue, or shut the engine off if the O2 sensor went faulty and can't regulate the smoke pollution, or disable starting if the knock sensor triggered the DTC as there may be no oil in sump which could amount to a very expensive engine repair. In the case of the latter, the oil light should have illuminated long before the knock sensor shuts the engine off. However I have encountered a problem with the wires that plug into the oil sensor that became brittle due to engine heat and  subsequently broke off. As a result the sender  sent the low oil condition but it never arrived at the the ECU hence did not turn-on the oil-low light. I only became aware of this when my EPC light went on due to the knock sensor. See picture in blog.   More ...