ON-BOARD DIAGNOSTICS 

A few days ago I was driving behind a string of cars through Liesbeek Parkway when I was startled by several drivers repeatedly  hooting at an Audi A4 driving in front of them to get out of the way or change lane. The Audi A4 that was holding up the traffic had a Guateng registration plate and  my first impression was that its occupants got lost at the spaghetti junction fly-over, not knowing which off ramp to take.

However when these impatient hooting drivers finally overtook the Audi A4 and I got to drive behind it;  I then realized that the Audi A4 was in fact in Limp Mode. Its driver was attempting to get to the shoulder of the road from the centre lane and the traffic just wasn't easing up.

In my opinion, these impatient driver just weren't aware that when a vehicle goes into Limp Mode it cannot go any faster than it's already going even though its driver was flooring the accelerator pedal. And I may add that ignorance about Limp Mode is no excuse, because its been around since 1996.

Vehicle Delivery Services Salvaged Limp Mode car

DRIVER COURTESY

Driver courtesy is very important to bolster safe driving conditions for everyone but an education regarding Limp Mode would be considered far more important. When a car suddenly reduces speed after driving at normal speed, it could be one of several reasons; among which could be steering vibration due to a puncture. Or the vehicle ran out of fuel. Or the engine may have switched off due to a dead battery caused by either alternator issues or snapped fan belt. 

Or the engine may be overheating, or the driver heard a disturbing noise coming from the engine. Or it could be an electrical fault like a faulty fuel pump or an ignition system failure like a defective engine or transmission control unit. Or the driver could have fell ill behind the wheel, to mention but a few of the myriad of reasons why a vehicle could stall or it may have entered in Limp Mode. 

AUTOMATIC TRANSMISSIONS

The engines of cars with automatic transmissions can sometimes switch off mid travel for some obscure reason. The only option the driver has, is to pull off the road, bring the car to a halt, place it in park or neutral to restart the engine. I know of someone who shifted his automatic transmission into neutral when the engine cut out mid travel, restarted the car and shifted it back into drive. This caused his car to almost come to a stand-still instantly causing the wheels to screech as the engines inhibited the transmission.  This type of action can and probably will damage the transmission subject to the gearing system inside and should never be done. Unfortunately no On-board diagnostics makes provision to prevent this.

When an engine cuts out at say 100kph both the power steering and vacuum boosted brakes stops working, thereby making steering difficult and the braking inefficient. It is therefore best to pull off onto  the shoulder of the road and check what the problem is an remedy it before continuing on your journey.

ON-BOARD DIAGNOSTICS

On-Board Diagnostics does a pretty decent job of protecting the engine and transmission against damage by limiting  acceleration, keeping the engine revs to a maximum of 2000 (RPM) and speed to about 45kph - aka Limp Mode. When Limp Mode is enabled, it may lock an automatic transmission  in low gear and even disable both heating and air conditioning. Yet keeping the engine running so that it can be driven to a repair shop.

However, as clever as an ECU is,  it doesn't do anything to alert the driver of the car that follows close behind. Considering tail lights, brake light, reverse lights and  indicators represents a language used by vehicle drivers for those  following behind, to indicate their driving intentions. This light language that's been around for the better part of the automotive industry's existence yet it still haven't come-up with an appropriate and safe warning sign/method for Limp Mode. 

LIMP MODE INDICATOR

To remedy this, car manufacturers could include flashing hazard lights or perhaps fit an LED Display with a scrolling message along the the rear window as an alert to tell the driver following behind that the car in front of it has gone into Limp Mode. Alternatively, electronics savvy car owners can fit their own aftermarket hack by identifying the switching output of the appropriate automotive  High Side Switch (HSS) responsible for protection and diagnostics inside the ECU when Limp Mode is enabled.

Automotive industry High-Side Switches /Drivers - Integrated Circuit 

This may not be as easy as it may seem or sounds because of the myriad of automotive chip manufactures, each pushing their our integrated circuits (ICs) running custom/propriety software, among which are Infineon Technologies AG,   Robert Bosch, Qualcomm, Renesas Electronics Corporation (Intersil), NXP Semiconductors,  STMicroelectronics, Texas Instruments, Intel and Microchip Technology Inc, etc.

However, most of these manufacturers produce Power Switches and incorporate Open Load Detection in their design so that they can perform open-circuit diagnosis on loads, such wiper motors, fans, head lamps, fuel pump, mirrors, actuators in general and LED lights while  the load is enabled or disabled. Open load diagnosis is probably the most important function of the software driven High-Side Switch (HSS) and Low-Side Switch when wired in a specific configuration which allows for currents from 5mA to more than 10A to be accurately detected.   

As such able to generate a hardware signal (Limp Mode signal) that can directly control the hardware without the participation of the microprocessor in the ECU. This output can be used to as either a digital High of Low (using CMOS inverter) to drive a LED display that flashes LIMP MODE..... LIMP MODE..... LIMP MODE.....

VW POLO CANBUS

If you own a Volkswagen Polo, you more likely that not already know that a Controller Area Network (CAN) bus is an automotive wire network loosely referred to as a bus. The word "bus" comes from the electrical power distribution sector where bus-bars were considered a metalic strip made of copper, brass or even aluminium that served as a source of electric power to the load. 

CAN BUS

However CAN Bus is more akin to Ethernet than a bus-bar. Ethernet is a computer networking technology using Unshielded Twisted Pair cable (UTP) either CAT5 or CAT6 which is now commonly used in local area networks capable of sending  IPv4 / IPV6 packet across its networks at speeds ranging from as slow as 10Mb/s to as fast as 1000 Gb/s, hardware dependent of course. 

Twister pair electrical wires with various colour tracers.

Likewise CAN is a network technology commonly used in automotive networks capable of sending CAN-frames across its network at various speeds, again application dependent. It is essentially a  very reliable multi-master arbitration free serial bus, connecting numerous Electronic Control Units (ECUs) aka nodes together.

CAN BUS vs ETHERNET

The big difference between the two, is that Ethernet is an 8-wire bus comprising of 4 unshielded twisted pairs of wire, each with a specific colour coding, whereas CAN has only a single unshielded twisted pair of wires also with a specific colour coding. The CAT5 protocol insists on 2 twists per centimeter and CAT6 with more twists per centimeter whereas the CAN protocol insists on a 1 turn per centimeter. The lay of these wires are very specific and necessary to reduce or cancel interfering signals picked up from the environment by them, which is more commonly referred to as "crosstalk".

CAN BUS HIGH & LOW

Bearing in mind CAN comes in two varieties used for different functions, viz CAN-High (CAN-H) and CAN-Low (CAN-L).  CAN-H is used for the Powertrain, the Convenience and Infotainment buses. 

Whereas CAN-L is used for the rest of the bus wiring.  Both CAN-High and CAN-Low uses different colour wires for different makes of vehicle. For example:-

Manufacturer        CAN High        CAN Low

Mercedes                  Brown/red         Brown

Volvo                        White                Green

Vauxhall                   Green                White 

BMW 1 & 3             Green/orange     Green 

BMW 5 & 6             Black                 Yellow 

Porsche                     Yellow              Black

The big difference between the three buses for VW,SEAT, Skoda and Audi is that:-

1) The Powertrain bus wires interconnected to all the powertrain modules / nodes are coded Orange & Black CAN-H 

2) The Convenience bus wires interconnected to all the convenience modules / nodes are coded Orange & Green CAN-H 

3) The Infotainment bus wires  interconnected  to the infotainment modules / nodes are coded Orange & Violet /Purple CAN-H 

4) CAN-L bus wires to all the interconnected convenience modules / nodes are coded Orange & Brown. (Electronics colour code 31)

REPAIRING WIRES

CAN wires are typically multi-strand 0.35mm to 0.5mm square with 120 ohm termination impedance, capable of transmitting information using two complementary signals which makes them even less prone to crosstalk. But thin wires are prone to break and if and when they do, it is recommended  that when repairing these CAN Bus wires, that both wires must always remain the same length and of equal thickness. 

Implying CAN BUS is extremely unforgiving. So, when wire 1 of the pair is broken, wire 2 should also be cut and the piece of wire added in-between must be exactly the same length; and that the lay length of 1 turn per centimeter must be observed. 

ELECTRICAL INTERFERENCE

Failure to do so, may created a discrepancy in the wire length of the one wire in the twisted pair as well as in their differential voltages, hence result in network errors — ground noise, electrical interference, hum, buzz,  spark plug spikes — cannot and will not be appropriately cancelled. 

Whenever repairs are made to any CAN Bus wiring, it is highly recommended that all CAN Bus wire repairs are covered and highlighted with yellow insulation tape to signify to anyone doing successive work, that a previous repair was carried out. 

Electronic Power Control (EPC)

It was very surprising to discover how many thousands if not millions of car owners out there, have no idea exactly what  Electronic Power Control (EPC) is. Yet most of them would like to know what the Electronic Power Control (EPC) circuit really does , more especially the Volkswagen, Audi, Seat and Soda owners. 

Considering they've been plagued by the Electronic Power Control (EPC) light, limp mode, DTC errors and poor engine performance to the point of frustration and panic for a number of years. Nobody seems to be able to give them good advice or practical guidance; and in many cases not even the Volkswagen, Audi, Seat and Skoda agents can. 

Leaving VW owners confounded, disappointed and disillusioned by their choice in cars, which results in so many car owners swearing, never to invest in VW brands ever again.

Unscrupulous motor mechanics tend to take advantage of these situations, recommending that the car owner brings their car to them as soon as possible before damage occurs to the engine.  Whereas in fact, the Electronic Power Control (EPC) is a safety circuit designed to prevent damage to the engine. 

When the  Electronic Power Control (EPC) mode does engage, it can and often does affect the car's stability and cruise control and torque circuit giving the impression there is a lot more wrong than there actually is. 

Since the Electronic Power Control (EPC) is "yellow" and not red, it acts more as an advisory light rather than a warning light, even though everybody tends to call it a warning light. A  flashing amber light is considered a "warning signal" but still doesn't have the danger status of "red warning light". 

 


Technically the "yellow" Electronic Power Control (EPC) light is in fact  amber which is a blend between orange and yellow. Car dashboard light colours can be roughly divided into three categories. 

Warning lights are Red in colour. Advisory lights are  amber in colour and information lights are generally either white, green or blue in colour. Having said that, its simple to understand that amber implies that you should keep an eye on, or be prepared for either  a reduction in power or  interruption to power.

Hence, Amber lights are used as Indicator lights (flashers) on cars for the turn signal and hazards. Amber lights are also used by roadside breakdown vehicles to alert drivers. An amber traffic light is generally considered a cautionary light, signalling  readiness to stop. Much like an amber  traffic light does. 

Now that you know what the colours of the lights imply, allow me to give you the low-down on Electronic Power Control (EPC) itself. EPC is an acronym and it is the official abbreviation for Electronic Power Control. 

Electronic Power Control is an embeded system, specifically designed into electronic circuits that permits it be part of a larger electro-mechanical system.  An Electronic Power Control system can also simply be described as a self-contained "feedback" circuit.  

It can even be further  explained, as a microprocessor based electronic circuit -or a computer if you like- that alters its output bias based on its inputs. Its "status quo" or current baseline is taken as a reference point and the objective is to control its operation within its predetermined parameters, and as close as possible to the said baseline, based on the signals from its inputs. 

Should any of these inputs, that predominantly come from sensors fail, for whatsoever reason, the computer circuit wouldn't be unable to complete its processes and would either enter into a "compensatory state", a "warning state" or an "error state". But more about this later!

The Electronic Power Control circuit has become standard equipment as part of the OBD-II (On-board Diagnostics 2) system in all modern day cars, manufactured since 1996. The Electronic Power Control is an integral part of every computerized ignition and engine management system, embedded into the ECU (elcectronic computer unit). 

The Electronic Power Control (EPC) dashboard advisory light is also part of this system and is normally activated by errors in the vehicle's torque circuit but not exclusively. The Electronic Power Control (EPC) light is  actually  a "new" addition to the plethora of light on the more modern vehicle's dashboards, a light  that gives any driver a sense of despair when it turns on. 

But more about that later ...

However, since a full blown explanation is outside the scope of a single blog-post, it is imperative that you need to read  every blog installment or the entire blog to get the full Electronic Power Control (EPC) picture.

____________________________________________________________________

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On-Board Diagnostics

All about On-Board Diagnostics

On-board diagnostics are here to stay and any amount of wishing will not make them go away. Virtually every  car on the road today is fitted with one. The main objective behind having on-board equipment installed in automobiles is to control and  limit the level of harmful emissions emitted by these cars. Eco friendly motoring is the new way of keep the global carbon footprint to a minimum. Every motorist is responsible for their own. So when the check engine turns on, the on-board diagnostic equipment is trying to tell you that your car is failing its emission test and that it should be repaired before its going to drive properly again.

best obd scanner - There is no such thing as the best OBD scanner. But there is the best OBD scanner for a specific brand of car. For example VCDS is the best for Volkswagen (VAG) whereas  iCarsoft i980 is better suited for Mercedes Benz and BMW Scanner v1.4.0 OBD2 / OBDII Diagnostic Interface is best for BMW. LAUNCH, VAS 5054A ODIS,  AutoBoss, TOAD, MaxiDas, etc, are multi car diagnostic systems and are more suited for workshop use than DIY. There are plenty of DIY scanners among which are Autel MaxiScan MS509, Innova 3100,  Konnwei KW820, PowerLead Cadt PL-OM580, AutoPhix OB123, Acton CP9575, and hundreds of others, any one of which would probably the best scanner for a car owner. 

bluetooth obd - most likely refers to ELM 327 Bluetooth OBD2 / OBDII for Android that works pretty well with downloadable apps like OBD Auto Doctor, OBDeleven, OBD eZWay, OBD Car Tracker, OBD Fusion and OBDLink etc. This turns your cellphone or tablet a niffty diagnostic device.

car obd - refers to the on-board diagnostic system all car makers are obligated to install in vehicles manufactured after  1996 and beyond.

car obd reader - refers to an app or a hardware device that connects to a car via an interface cable or via bluetooth or WiFi

obd - is an automotive term referring to a vehicle's self-diagnostic and reporting ability.  

obd adapter - is normally a cordless bluetooth enabled adaptor that plugs into the car's 16 Pin DLC much like the ELM327 does. There are severa dozen manufactures who make them, amongs which are the Ozzy Gear OBD2 Scanner Bluetooth, Hikeren OBD2 Bluetooth Module, iAutomobil OBD2 Bluetooth Module, Foseal Mini OBD Bluetooth Scanner Adapter, Panlong Bluetooth OBD2 Scan Adapter, BAFX Products 34t5 Bluetooth OBDII Scan Tool.

obd android - there several OBD android devices. Vgate Bluetooth 4.0 OBDII is a Code Reader for both IOS & Android,  Hikeren Mini Bluetooth OBD2 is another  Car Scan Tool for android and HH OBD Advanced ELM327 OBDII V1.5 is yet another android Bluetooth Diagnostic Tool.

obd bluetooth - is the bluetooth enabled version of the scanner described above which is commonly used with a cell phone / tablet apps, and can also work with a bluetooth enabled laptop.

obd bluetooth adapter - is just another term use to refer to an OBD android / bluetooth adapter or  obd bluetooth android adapter.

obd cable - is a physical interface that plugs into the car's DLC. For example, VAG-COM V409.1 OBD OBD2 USB Cable is an OBD cable and so is KKL OBD2 USB Diagnostic Cable  both used specifically for Audi, VW, SEAT and SKODA.

obd car - Any car with either and OBD-I or OBD-II system installed. There are older cars that are completely devoid of diagnostics.

obd codes -  Are On-Board Diagnostic Codes, sometimes referred to as fault codes

obd code reader - is a handheld DIY device that purely extracts data from the ECU bus but can alter the data nor write it back to the ECU.

obd connector - refers to the DLC fitted under the dashboard close to the drivers seat. It can easily be identified by its light purple colour in VW's.

obd device - BMW motorcycle combo - OptiMATE  canbus connector is an OBD device and so are most of the adapter, cables and bluetooth connectors mentioned above.

obd diagnostics

obd reader - normally a hand held deice capable of reading OBD data from the car's ECU but not able to write back to it.

obd system - is a standardized microcontroller based system installed in cars that continually monitor its emission control systems, by using engine mounted electronic sensors and feed back from the catalytic converter 

obd diagnostic interface - refers to the USB to 16 pin DLC cable, that connects between the car and the laptop computer used to interrogate the ODB system.

obd interface - as above


obd i scanner - OBD I scanners are used on pre 1996 cars. It's been succeded  by OBD II.

obd ll - sometimes called OBD eleven, but its just a play on OBD-ii in upcase Ls. There is a bluetooth android device named ODB eleven.

obd ii - Is sometimes written as OBD 2 and is the current version of automotive vehicle On-board Diagnostics introduced in 1996 which superceded OBD 1 used in cars prior to that.

obd ii scanner  - refers to any an all devices capable of interfacing with the On-Board diagnostic system of a car used to read error codes.

obd port - The connector  fitted under the dashboard or behind the ashtray inside the car where the bluetooth adapter or the OBD inerface cable plugs into.

obd scanner - can either be a handheld  hardware device or a laptop based software /software device that interfaces with  the car's DLC, capable of reading the ECU, displaying DTCs, etc, and can either be OBD1 or OBD II.

obd scan tool - see obd scanner above.

obd tester - is an OBD scanner, that can take the form of a dedicated handheld device, or a computer based scanner or cellphone or tablet based scanner.

obd tools - refers to a collection of either diagnostic software or 

obd wifi - a codless device much like a bluetooth ELM 327 but that is rather WiFi enabled.

I liked a @YouTube video https://t.co/ArNrcfsGho OBD 2, On-board diagnostics, CARGURU, How to Diagnose your Engine, error

— Naseeb Singh (@kvnnaseebsingh) June 22, 2017

DIAGNOSTIC TROUBLE CODES

DIAGNOSTIC TROUBLE CODES

Your car has been misbehaving of late. Somehow she just doesn't seem to perform like she did in the past. It is very likely that there is a problem with your car and that she already threw an error code, now stored in its OBD (on-board Diagnostics) system. Fortunately this stored data can be retrieved via the diagnosis interface because diagnostic error codes have been standardized globally. Implying that the stored data can be retrieved with any Generic Scan Tool. Virtually every VW service center and even some private mechanics have one or more. Many private individuals have also invested in scan tools  because automotive repair cost have just skyrocketed of late hence they prefer to do the repairs themselves. I've been doing all my VW repairs for the past 8 years. 

OK, so now that youv'e done a diagnostic scan of your car, and retrieved the diagnostic scan codes, the printout looks like a foreign language. You desperately need help to understand what it means but you are no nearer to solving the misbehaving problem with the scan in hand, than you were without the scan. Don't worry, after explaining the basics of scan analysis, you will have a decent idea how to interpret your particular scan and perhaps even do the repair yourself before deleting / clearing the error code.

Low cost Diagnostic scan tools from various manufacturers.

Before we start to analyse the scan there are a few things that I need to mention. Diagnostic errors or more correctly DTC (diagnostic trouble codes) are numerous and fall into to categories, viz Generic fault codes / manufacturer-specific fault codes. However, there is a third category specific to VAG vehicles, though many mechanics also consider them as manufacturer-specific. But I will expound on this later. Fault code are divided into four categories viz, P, B, C and U One of these four alphabetical letters always precede  four numerals  and are thus referred to as an alphanumeric  code or just code for short. The P category is by far the most interesting. Both Generic fault codes and  manufacturer-specific fault codes are applicable to all OBD-II vehicles but manufacturer-specific fault code definitions vary from manufacturer to manufacturer and are also different to VAG codes.

P CODES

The P stands for powertrain, meaning the car's engine and gearbox / transmission.  So any and all preceded by a P is associated with engine or transmission problems. For example, P0100 is a powertrain code that correlates to  'mass  air flow circuit problem'. P0200 is also a powertrain code that correlates to an 'open circuit injector'. P0300 is a another powertrain code that correlates to the 'detection of random/multiple cylinder misfires'. P codes start at P0000 and range to P3999.  Generic P codes are a subset of P codes and start with either P0xxx, P2xxx and P34xx - P39xx, implying that P codes  staring at P1xxx and P30xx- P33xx are not generic but manufacturer-specific codes. 

As can be seen above, in the Powertrain system , the first digit after the P indicates  whether or not the code is generic or manufacturer-specific. The second digit identifies a specific area of the vehicle that's at fault. The powertrain components are divided into 9 distinct area as can be seen below. ( Refer to diagram below)

1xx Fault codes related to 'Fuel & Air Metering'
2xx Fault codes related to 'Fuel, Air metering & Injection Circuit'
3xx Fault codes related to 'Ignition System & Misfire Detection'
4xx Fault codes related to 'Auxiliary Emission Controls'
5xx Fault codes related to 'Vehicle Speed & Idle Control System'
6xx Fault codes related to 'Computer Output Circuit'
7xx Fault codes related to 'Transmission / gearbox related faults'
8xx Fault codes related to 'Transmission / gearbox related faults'
9xx Fault codes related to 'Transmission / gearbox related faults'

The third and fourth digits identify the specific component involved with the fault. This can be referenced from a complete list of codes that can be downloaded from various OBD sites. For example, www.outilsobdfacile.com/ www.obd-codes.com/trouble_codes/ www.launchtech.co.uk  www.trouble-codes.com/ www.automotive-technology.co.uk 

The fault code doesn't identify the actual component that's causing the fault but rather narrows it down the area that needs to be investigated. Often times the sensor that does the detection actually goes faulty. For instance, the crankshaft position sensor and camshaft position sensors are prone to failure, causing the engine to stall or  fail to start. 

OBD-II Diagnostic Trouble Codes Explained

B CODES

B stands for Body and includes the Air Bag and other mechanical / electronic components not associated with the engine and transmission/gearbox. For example, B0005 is a body error code and correlates to a 'park switch circuit malfunction'. B0530 is another body error code and correlates to a 'stuck fuel level sensor'.  Generic body trouble codes start with either B0xxx or B3xxx, again implying that B codes starting with B1xxx and B2xx are manufacturer-specific codes.

C CODES

C stands for Chassis and include the ABS and other mechanical / electronic components not associated with neither  the engine and gearbox nor the body. For example,  C0281 is a chassis error code and correlates to a 'brake switch circuit malfunction'. C0238  is a chassis error code and correlates to a 'wheel speed mismatch'. The generic network trouble codes for C start with  either C0xxx or C3xxx. C codes starting with either C1xxx or C2xxx are manufacturer-specific codes.

U CODES

U stands for User Network. Initially the U stood for “undefined” but is now network-related. For example,  U0109 is a network error code  and correlates to 'lost communication with fuel pump control module'. U0405 is another is a network error code  and correlates to 'invalid data received from cruise control module'. The generic network trouble codes for U start with  either U0xxx and or U3xxx, again implying that codes starting with U1xxx and U2xxx are manufacturer-specific codes. 

VAG CODES

Now VAG codes on the other hand  range from 00000-65535 and don't have any letters. It is just a 5 digit numeral and coincides with the list of both generic code and manufacturer specific codes. For example:-

VAG code 16385 coincides with generic code  P0001 - Fuel Volume Regulator Control Circuit Open

VAG code  16389 coincides with generic code  P0005 - Fuel Shutoff Valve (A) Circuit Open


VAG code   16434 coincides with generic code  P0050 - Oxygen Sensor Heater Bank 1/2 Control Circuit

Generic fault code P0403 equates to a VAG 16787 - EGR Valve Malfunction

Generic fault code P0571 equates to a VAG 16955 code - Brake Switch Signal Implausible 

Generic fault code P1690 equates to a VAG 18098 code - Malfunction Indication Light (K83)


Generic fault code  P1814 equates to a VAG 18222 - Transmission Pressure Control Valve open or Short to Ground 

Generic fault code P0032 equates to a VAG 000050 - Oxygen (Lambda) Sensor Heating Circuit Short to Plus 

Generic fault code P0720 equates to a VAG 17104 -  Transmission Output Speed Sensor (G195) Circuit Malfunction


Generic fault code P1517 equates to a VAG 17925 -  ECU Power Supply Relay  Malfunction 

Looking at your scan printout, especially if it's a VCDS scans, it may be quite evident that there are two or three data systems delivering the same data but in a slightly different format. The clipping below purely displays VAG codes with a numeric description.

Address 17: Instruments Labels: Redir Fail!
Part No: 6Q0 920 820 H
Component: KOMBI+WEGFAHRSP VDO V05 
Coding: 00141

6 Faults Found:
01312 - Powertrain Data Bus 
37-10 - Faulty - Intermittent
01314 - Engine Control Module 
49-10 - No Communications - Intermittent
01316 - ABS Control Module 
49-10 - No Communications - Intermittent
01321 - Control Module for Airbags (J234) 
49-10 - No Communications - Intermittent
01322 - Control Module for Multi-Function Unit (MFA) (J501) 
49-10 - No Communications - Intermittent
01309 - Power Steering Control Module (J500) 
49-10 - No Communications - Intermittent


The clipping below displays both generic and VAG error codes as well as a fault description in number code.

Address 01: Engine        Labels: 06A-906-032-BBW.lbl
Part No: 06A 906 032 RJ
Component: 2.0l R4/2V      G   6505  
Coding: 00003
   
4 Faults Found:
17837 - Circuit for Brake Vacuum Pump 
P1429 - 35-00 - Open Circuit
16452 - MAP/MAF  Throttle Position Correlation 
P0068 - 35-00 - 
16804 - Catalyst System; Bank 1 
P0420 - 35-00 - Efficiency Below Threshold
16395 - Bank 1: Camshaft A (Intake) 
P0011 - 35-10 - Retard Set point not Reached - Intermittent

The clipping below  shows VAG 5 digit codes and description numbers.

46 Address: Central Conv. Labels: 1C0-959-799.lbl 
Part No: 1C0 959 799 C 
Component: HLO Komfortgerát 1H 0003 
Coding: 00258 

3 Faults Found: 
01330 - Central Control Module for Central Convenience (J393) 
53-10 - Supply Voltage Too Low - Intermittent 
00849 - S-contact at Ignition / Starter Switch (D) 
25-00 - Unknown Condition Switch 
01359 - Internal Central Locking Switch; Passenger Side (E198) 
27-10 - Implausible Signal - Intermittent

As can be seen in two of the examples above, there are also numbers like, 27-10, 37-10, 49-10, etc. The first two digits of each set of numbers are the numeric equivalent to the text meaning 'Implausible Signal, 'Faulty  and 'No Communications' respectively. Each set of numbers ends in -10, which means 'intermittent'. Hence 27-10 means Implausible Signal - Intermittent, 37-10 means  Faulty - Intermittent and  49-10 means  No Communications - Intermittent. Fault codes can also have a -00 suffix in place of -10 which implies a definite fault (not intermittent). Occasionally you would encounter just a hyphen (-). This implies that the scan equipment could not retrieve further details about the fault and just left it blank. 

Volkswagen Electronics

VOLKSWAGEN ELECTRONICS

AUDI  MODULE CODING

Electronics has taken over the modern day car, a trend that started prior to 1994. Since then  motor vehicle electronics technology has taken on a completely different form. With the advent of OBD (On-Board Diagnostics) there has been strides to standardize automotive electronics in all vehicles with relative success. With the arrival OBD II automotive electronics standardization was close to uniform, however there were other derivatives, among which was EOBD (European OBD). Thereafter, CAN-Bus was introduced which is now the defacto standard for all cars built after 2008 internationally. All cars built from 2012 only sports CAN-Bus,  and are not backward compatible to older ODB II protocols, like KWP2000 for example. This move implies every auto technicians who financially invested in ODB II scanners will have to get the latest equipment in order to scan the latest cars. Just look at the Audi Q7 with its 50+ electronic modules all of which are CAN-Bus only. 

Audi Q7 has more than 50 Electronic Modules.

The hexadecimal list of Electronic Modules below are just an idea of what can be expected in current and future motor vehicles many of them having as many as 24 different module versions, many modules are incompatible with the various models of Audi, VW, Skoda and SEAT, each with its own features and coding.

01: Engine

02: Auto Trans

03: ABS Brakes

05: Acc/Start Authorization

06: Seat Memory - Pass Side

07: Control Head

08: HVAC

09: Electrical Control

0E: Media Player 1

0F: Digital Radio

10: Park/Steer Assist

11: Engine II

13: Auto Dist. Regulation

14: Susp. Elect

15: Airbags

16: Steering Wheel

17: Instruments

18: Aux. Heater  

19: CAN Gateway

1B: Active Steering 

1E: Media Player 2  

20: High beam assist

22: All Wheel Drive

25: Immobilizer

28: Heating / Air Conditioning (Rear)

2E: Media Player 3

30: Special Functions II

34: Level Control

36: Driver's Seat

37: Navigation

3C: Lane Change

3D: Special Function

42: Door Elect, Driver

46: Central Convenience

47: Sound System

4F: Centr. Electr. II

52: Door Elect, Pass

53: Parking Brake

55: Headlight Range

56: Radio

57: TV Tuner

5C: Lane Maintenance

5F: Information Electr.

61: Battery Regul.

62: Door, Left Rear

65: Tire Pressure Monitor

67: Voice Control

69: Trailer Controller

6C: Back-Up Camera

6D: Trunk Electronics

6F: Comfort System II

72: Door, Right Rear

76: Park Assist

77: Telephone

AUDI : - SOME ENGINE CONTROL UNITS AND CODINGS

Engine:

Controller:     8E0 909 518 A,
Coding:         0011581 or 0016711

Controller:    8E0 909 518 AA

Coding:         0011501

Controller:    8E0 909 518 AC
Coding:        0004501 / 0004581

Controller:     8E0 909 518 AF
Coding:         0016701 / 0016751 / 0016581

Controller:     8E0 909 518 AK
Coding:         0016711 /  0016751 /  0016501

Controller:     8E0 909 518 AL
Coding:         0011584

Controller:     8E0 909 518 AS
Coding:         0011511

Controller:    8E0 909 518 AQ  
Coding:        0011501

Controller:     8E0 909 518 F
Coding:         0016701 or 0016751

Controller:     8E0 909 518 G
Coding:         0016581

 AUDI Automatic Transmission 
codings will be covered in Future Blogs.

VIN Number identification 
will also be covered in Future Blogs.

Volkswagen’s new modular architecture 
will also be covered in Future Blogs.