AUTEL D900 CONTINUED

AUTEL 900

This blog is a continuation of a previous blog named AUTEL D900 SCAN TOOL in which I outlined its indispensability and necessary tool to repair any VAG vehicle. Anyway, I hooked up the D900 2015 version to my polo classic 2.0l highline. As can be seen below, its software is already at version 15.7 and dated July 2015 meaning that it's a huge improvement compared to the 2011 model. There are 30 vehicle manufacturers  listed in the Autel 900 menu, the 28th of which is Volkswagen and the last selection is other, meaning any vehicle not listed. I did a DTC scan but there was none stored in memory. Neither was there any vehicle information nor freeze frame data. Compared to VCDS the live data is accurate. I was interested to see the coolant temperature increase while the car idled and that's exactly what I saw. 

The OBD2 monitors are abbreviated and I dropped in a list for ease of identification below. Unfortunately I can't demonstrate the DTC feature since there were not DTCs to display. I verified with my VCDS to make sure that the D900 isn't saying that there isn't any while there may be some.

Abreviations o the various OBD2 monitors.

In my opinion the D900 is good value for money. Initially  I was sceptical that it didn't support Polo but it clearly does. It supports Audi and Porsche but doesn't specifically list Skoda nor Seat.  It may read then under other but I will have to check this and this post later. A list of VAG cars that it supports can be seen here.

The D900 laying on the passenger seat.

The D900 switch on, first screen.

D900 supports Volkswagen and Audi 

D900 has 7 functions, 6 of which can be seen here

D900 reads MIL status, Freeze frame and I/M readiness

Live data from my VW polo 

More live date from my VW Polo

The following 3 pics are  self explanatory

More live data from my VW Polo

AUTEL 900 works on the following list of VW Polo Highline Cars

vw polo highline
swift zdi vs vw polo highline
volkswagen polo 1.2 l highline
volkswagen polo 1.2 l highline d
volkswagen polo 1.2 mpi highline
volkswagen polo 1.2 tsi highline
volkswagen polo highline 1 4
volkswagen polo 1.4 5p. highline
volkswagen polo 1.4 highline 75cv
volkswagen polo 1.4 highline 80cv
volkswagen polo 1.4 tdi highline 75cv
volkswagen polo 1.4 tdi highline 80cv
volkswagen polo 1.6 l highline
volkswagen polo 1.9 tdi highline 96kw for sale
volkswagen polo 6n2 highline
volkswagen polo classic 1.6 highline
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AUTEL D900 SCAN TOOL

AUTEL D900 SCAN TOOL

The modern day car in its current incarnation has increasingly become more and more electrotechnical than mechanical and technological advancements are constantly on the incline.  It is therefore  quite appropriate to say that vehicle owners need to become electromechanical savvy. In my opinion, the way forward is to invest in a scan tool for your particular make and model car. Since most people are familiar with Cell Phones, Decoders, Set Top Boxes, PVR, DVR and Televisions with various menus, or computers, access points and routers  with various wizards, navigating a scan tool would be relatively easy. A scan tool is an indispensable device for modern car diagnostics and is a technological marvel that's going to save you time and money, but only if you are willing to embrace the technology. 

In a previous blog I discussed VCDS which I think is a really fantastic piece of software with its hardware interface combination specific to VAG vehicles. The amount of Onboard information that is accessible with VCDS is astounding and it is literally beter than the factory  VAS Scan Tool used by VW /AUDI /SKODA / SEAT agents. In fact, in some cases VCDS  will even retrieve more faults than the VAS tools.  Be that as it may, as fantastic as VCDS is, it has major shortcomings for vehicle owners in general. Since VCDS is VAG specific, all other vehicle owners are at a loss to its technical capabilities and would have to look at other scan tools from  companies like  Auto Boss, Launch X431, Autel Maxidas DS708, Pro-Link iQ,  Mentor Touch ET6500, OTC Pegisys, Craftsman - 20899, G-Scan Oceania, Bosch 3824, etc, who produce commercial multivehicle scan tools. These companies cater for the automotive service industry since their scan tools are quite pricey and far beyond the budget of the average car owner.  If VCDS was multivehicle, it would be as good if not better than most commercial scan tools. However, since this is not the case,  Autel has come to their aid of the average car owner. Autel has a low cost handheld scan tool that is multivehicle compatible that supports the following list of vehicles.

Acura, Audi, BMW, Buick, Cadillac, Chevrolet, Chrysler, Daewoo, Dodge, Eagle, Ford, Geo, GMC, Honda, Hummer, Hyundai, Infiniti, Isuzu, Jaguar, Jeep, Kia, Land Rover, Lexus, Lincoln, Mazda, Mercedes Benz, Mercury, Mitsubishi, Nissan, Oldsmobile, Pontiac, Porsche, Plymouth, Saab, Saturn, Scion, Suzuki, Toyota, Volkswagen, Volvo.  

I acquired the 2015 version because of its versatility because it supports several models of each of the above mentioned vehicles. I wanted it to diagnose my Renault but discovered that it unfortunately does't support Renault and even more surprisingly it doesn't support my  VW Polo  2.0L Highline (9N) either but it does support the the following list of VAG vehicles.

Audi A3
Audi A4
Audi A6
Audi A8
Audi A8L
Audi All road
Audi Cabriolet
Audi S4
Audi S6
Audi S8
Audi TT

Volkswagen Beetle
Volkswagen Bora
Volkswagen Eurovan L5
Volkswagen Eurovan VR6
Volkswagen Golf A3
Volkswagen Golf A4
Volkswagen GTI
Volkswagen Jetta A3
Volkswagen Jetta A4
Volkswagen Passat
Volkswagen Touareg

I don't know if the previous years version (Autel D900 2012) supports older vehicles like 2002-2010, but am of the opinion that all newer scan tools are backward compatible though I may be wrong. Anyway, the Autel scan tool is really cool, it comes with a mini CD containing a pdf file of all supported vehicles. I would have thought they would include a list of generic DTCs for Chassis / Powertrain (P-codes), Body (B-codes)  and Network (U-codes) for easy of identification. What this implies is that you will have to either find these lists online, save them as pdfs or print them or access the internet resources to identify the codes every time you car throws you a DTC.

CONTINUED

AUDI OIL PUMP PROBLEM

AUDI A4 ENGINE NOISE

For the past week my sister's Audi A4 2.0L 2007 has been having issues. When it starts its engine sounds like a tractor engine but after about 15 secs it quietens down and sounds and idles perfectly normal. Ever since its engine oil and oil filter change some seven weeks ago by her friend. The "Engine oil pressure light" keeps turning on, after some 20 minutes of driving, accompanied by a beep from the pizzo electric buzzer. Thereafter  it repeatedly  triggers  unexpectedly,  actually giving her a fright every time it does. I ran a scan with VCDS and there was absolutely no sign of engine trouble or DTC from the engine. Except for ABS signal out of specification fault which is totally unrelated to oil pressure. So since there was no problem other than the engine  Engine oil pressure light that triggered daily she decided to drive the Audi in that condition and tolerate the beeping. 

I inquired about the oil that they used, thinking perhaps that if the  grade of oil was too thick, it would affect the oil flow and pressure.  She fetched the container which still had some oil in it from the garage to show me what it was and on inspecting the viscosity of the oil between my thumb and forefinger I was amazed by the crap they sell unsuspecting customers. It turned out that she bought SAE 10W/20 oil at the local supermarket off the automotive shelf because it was going cheap. The oil was so thin, it was virtually like water, it couldn't even form a drop at the end of my finger. I even asked her if they mixed paraffin with the oil and she said no. I looked at the writing on the container to see if it wasn't two stoke oil for lawnmowers but it wasn't. 

Audi A4 Oil Pump (Old Top - New Bottom)

I then knew that this was the cause of the problem. The oil was too thin and the oil pump had difficulty in getting enough oil to the cams, bushes and gears  resulting in the noise caused by excessive friction during the the first 15 seconds when started. I actually thought that the oil may be too thick, so that the  oil pump couldn't push through the required volume of oil per minute. After telling her what an idiot she was to buy this cheap crap oil, I begged her to get some VW 50300 Long Life Engine Oil from the Audi agents.  I even offered to drain the crap oil out her Audi, flush the engine, replace the oil filter and fill it with the correct oil. The VW 50300 Long Life Engine Oil does cost a lot more than regular oil put it has the advantage of 30000 km before the next change. Fortunately it costs less than VW Automatic Transmission Fluid

So after replacing the filter and filling up with the new oil, the Audi now sounds a lot better but it is still noisy. Not as loud as it was before and the duration of the noise reduced from 15 seconds to about 4 seconds. Its  going to cost her a new oil pump replacement within the next week or so, because driving with a suspect oil pump is asking for the engine to seize and heaven alone knows what that's going to cost to repair.

LIMP MODE Q&A

LIMP HOME MODE

When I initially bought my VW Polo 2.0L she was a thrill to drive. Her speed was instant, cornering was really good and road holding never better. She was a joy to drive, very unlike my VW Golf II, but then I started getting car troubles,  which were many and varied. My first encounter with VW agents was a disaster. After they "repaired" my EPC fault they charged me a ridiculous sum of money, only to experience the same EPC problem the following day.  After speaking to several of their mechanics, who collectively were unable to fix my car, I came to realize  that I was either far more knowledgeable about automotive electronics than all of them put together, or they knew very little about electronics.  This just put me off the agents completely and when I took my Polo to independent mechanical workshops,  I found the same to be true. I still remember how lost I felt when my VW Polo went into limp mode the first time and the second and the third and the fourth. I felt lost, stuck on the freeway, late for meetings, frustrated and miserable because I couldn't repair her like I did the VW Golf II due to the fact that the Polo had OBD-II. I  thought my VW Polo to be unreliable, there was a point that I feared driver her at night, and later started to hate  even diving the Polo.  I was literally on the verge of setting her alight. But them I decided to buy a Ross Tech cable and downloaded their VCDS and my Polo is a joy to  drive once again. The rest of this blog is devoted to 10 vehicles owners who have experiences similar trouble with their VAG vehicles ranging from Drive by wire problems, to EPC trouble, to DTC trouble Codes to CAN-Bus-issues to name but a few. 

DRIVE BY WIRE
Steve sent this:- Had the problem of no power, tried the technique described in your blog (disconnect battery, wait, reconnect, turn ignition key, wait, turn off, turn engine on, wait, press throttle...) - and it worked beautifully. Many thanks for your help, very much appreciated - particularly as you've probably save me many pounds. 

QUESTION? - DRIVE BY WIRE
Anonymous sent this:- I have a '07 Polo 1.4 16v BUD. I don't have any lights on the dash, but the engine seems really weak through mid revs and is using a bit too much fuel. When I hook up my OBDII there are no faults recorded but when I view the throttle position in real time it doesn't seem to open in a linear manner. As I press the pedal on the road, the throttle valve seems to open slower than the position of  the pedal. eg; 50% pedal = 30% throttle position, 80% pedal = 35% throttle, 95% pedal = 40% throttle, 100% Pedal = 100% throttle. As you can see WOT does give WOT at the throttle body, but I don't generally drive with my foot planted on the floor. I am confused why it does this as you would expect the throttle body to open the same amount as the pedal, could it need alignment? I am loathed to take it to the VW dealer for fault diagno$i$ so if anyone has any ideas????  Thanks 

ANSWER!
On drive by wire model vehicles the throttle doesn't open like legacy cable throttles because its electronically controlled. 

DRIVE BY WIRE
Durell  Dunn  left this:- I am currently experiencing the same problem with my 2003 polo,1.4. The car goes into limp mode and on some occasions switches off in traffic, hectic ! I will use your method. Thank you for saving me from going to a VW dealership, all I can do at this stage is do and hope 

DRIVE BY WIRE
Loci sent this:- Hi. I have a problem with my Volkswagen Polo 1.4 Tdi. It seems to have a good start but after I drive for around 35 minutes it loses the power so I could not pass 2000 giro. Thank you for your suggestions.

QUESTION? - DRIVE BY WIRE 
Anonymous asked:- My car is a polo 1.4 2012 model. When I start the car the EPC light switch on then I put gear to move the car but it limbs then I switch it off then start it again then the EPC light does not switch on then off I go... What could be wrong? 

ANSWER!
The trouble can be one of many things, among which are your accelerator pedal, throttle body, knock sensor, Fuel pump pressure, even a loose fuel cap. You need to check through each systematically but for that you at least need a scan of your vehicle.

ENGINE LIGHT COMES ON
Lee Kyprian left this:- Everyone who has ever owned a car has experienced the confusion and even panic which can arrive when your check engine light suddenly comes on.

QUESTION? VW ELECTRONIC POWER CONTROL
Abror Isoqov sent this:- Hello. My car is VW Golf 1.6 16v and I have a problem with acceleration it has no enough power. It accelerates very slow and at 5th gear it can get max 130 km/h. At neutral position when engine gets about 5000 rpm the EPC light comes on. After restarting the engine it goes off. Tester didn't determine any trouble codes. What can cause for this problem. I went about 7-8 auto services but any of them could help. But I didn't go to VW dealer because it will be very expensive. last time they charged me $125 just for diagnostic.  Please help me with this issue.   

ANSWER!
What you explaining is limp mode and everything else seems very odd. Because by the time the EPC light does go on, a DTC is already set which any scan tool should be able to retrieve. Unless there is a problem with you DLC wiring, so that communication between vehicle and scan tool is erroneous.

VW ERROR CODES
Steve Cain sent this:- Hi, vw polo 1.4tdi 2003, AMF engine code,  problem is that when driving at any speed, car looses all power, engine stuck on 1200 rpm, throttle pedal no response, glow plug heating light flashes, switch off & switch back on straight away, car drives normally, no warning lights. Can you shed any light on this problem, (driving my wife mad). Thanks, Steve 

ANSWER!
I have covered this problem quite substantially in previous blogs and it in your interest to ready through them.

WON'T REV
Anonymous sent this:- My VW Jetta 2002 1.8t stopped me on the highway and it refused to rev and the mechanic says it is the brain box. I don't understand is he correct?

ANSWER!
Yes he is correct, problem lies in the ECM circuit but not necessarily the ECM itself. Dude you need to get your car scanned to get a better idea of  the actual problem.

CAN-BUS
Hi! I read your blogs and saw writings from you  about the CAN bus protocol. I have a problem to understand something on my cars OBD connector and the CAN bus line. Can you please help me maybe? Can we talk about? When I connect my 2 channel  DSO to the OBD connector pin 6 and pin 14 ( CAN-H and L ) and pin 5 (GND) on my VW Polo 1.4D year 2003 I got this signal what I posted right now. But, when I do the same think on my Renault Clio 1.5DCI year 2003 I got the right CAN signal.  

ANSWER! 
The likely hood is that your VW Polo isn't CAN compliant because its still a 2003 and used KWP-1281 and KWP-2000 protocols.  All VW's after 2008 is fully CAN compliant.

VAG FUEL TRIM PROBLEMS

SHORT TERM FUEL TRIM ISSUES

Modern day OBD-II systems can be described as high-end electronic systems that "sort of" took the automotive industry by surprise. As such , there are so many motor mechanics that have not made the transition from technologies prevalent in older model cars to the technologies pervasive in newer model cars yet, and understandably some never will.  Several of these motor mechanics don't even own a scan tool and even fewer of them are able to interpret the DTCs and the results of a diagnostic scan. With the  result, that many VW owners took it upon themselves to become ODB-II savvy and even do their own automobile repairs. Many of whom have invested in low end scan tools like VAG COM, Actron, Nextech Carmen,  Foxwell, OBD Scan, Altar, etc, and others invested in high end scan tools like G-Scan, VCDS, Xtool, Launch, AutoHex, Autel and Auto Boss etc. Even though the VW service departments are equipt with the best diagnostic scan tools they tend to lack the technical personnel with the requisite expertise to understand them and effectively repair clients VW, Audi, SEAT and SKODA cars. Electronics has taken over the modern day car and being knowledgeable about electronics is key however not every car owner  is therefore not equipt to to analyse the diagnostic printout. As an example, lets take a look at the infamous VAG fuel trim problems list below. All of them very loudly shouts that the stoichiometric  ratio is off. Generic Short Term Fuel Trim (STFT) DTCs range from P0170- P0175 which are generic government required codes and Long Term Fuel Trim (LTFT) range from P1123-P1130, P1139-P1139,  P1151-P1152, P0166-P1167 and all are manufacturer specific.

SHORT TERM FUEL TRIM (STFT)

16554 - P0170 - Fuel Trim, Bank1 Malfunction
16555 - P0171 - Fuel Trim, Bank1 System too Lean
16556 - P0172 - Fuel Trim, Bank1 System too Rich
16557 - P0173 - Fuel Trim, Bank2 Malfunction
16558 - P0174 - Fuel Trim, Bank2 System too Lean
16559 - P0175 - Fuel Trim, Bank2 System too Rich

LONG TERM FUEL TRIM (LTFT)

17531 - P1123 - Long Term Fuel Trim Add.Air, Bank1 System too Rich
17532 - P1124 - Long Term Fuel Trim Add.Air, Bank1 System too Lean
17533 - P1125 - Long Term Fuel Trim Add.Air, Bank2 System too Rich
17534 - P1126 - Long Term Fuel Trim Add.Air, Bank2 System too Lean

17535 - P1127 - Long Term Fuel Trim mult, Bank1 System too Rich
17536 - P1128 - Long Term Fuel Trim mult, Bank1 System too Lean
17537 - P1129 - Long Term Fuel Trim mult, Bank2 System too Rich
17538 - P1130 - Long Term Fuel Trim mult, Bank2 System too Lean

17544 - P1136 - Long Term Fuel Trim Add.Fuel, Bank1 System too Lean
17545 - P1137 - Long Term Fuel Trim Add.Fuel, Bank2 System too Lean
17547 - P1139 - Long Term Fuel Trim Add.Fuel, Bank2 System too Rich

17559 - P1151 - Bank1, Long Term Fuel Trim, Range 1 Leanness Lower Limit Exceeded
17560 - P1152 - Bank1, Long Term Fuel Trim, Range 2 Leanness Lower Limit Exceeded

17573 - P1165 - Bank1, Long Term Fuel Trim, Range 1 Rich Limit Exceeded
17574 - P1166 - Bank1, Long Term Fuel Trim, Range 2 Rich Limit Exceeded

17582 - P1174 - Fuel Trim, Bank 1 Different injection times

THE DEFINITION OF A BANK

Before we continue, it is important to get certain definitions right. In 8 cylinder (W8) engines and 12 cylinder (W12) engines, 4 or 6 cylinders are staggered  aligned at a V-angle,  72 degrees in relation each other, thereby making the engine more compact.  Each staggered row of either 4 or 6 cylider has its own head,  which is called a "Bank",  hence Bank 1 and Bank 2. On the other hand VR6 engines cylinders are also staggered but has a single cylinder head, however the three left most side cylinders (odd numbers) are called "Bank 1" (passenger side left-hand drive) and the right most cylinders (even numbers) are called Bank 2. Four cylinder engines normally have 4 in-line cylinders but here as well, the odd cylinders are called Bank 1 and the even cylinders Bank 2 as can be seen in the "Chassic type: Skoda Fabia  1,2l/4V" below. But this configuration does apply to all 4 and 5 cylinders engines because in some engines all cylinders are referred to as bank 1. Looking at  the above P-Codes  P0170-P0175 it can clearly be seen that  P0107 refers to Bank 1 and is common to both  P0171 and P0172. And likewise P01703 refers to Bank 2 and is common to both  P01704 and P0175. This information allows us to determine which cylinder is bank is running rich or lean. Intermittent signals may be due to continuous STFT occurrences or the bad electrical connections at the o2 sensors. However, every time the engine is started the OBD-II system  does a self test on the O2 sensors,  and should the Check engine light not remain on, then the O2 sensor is probably not the culprit.

______________________________________________________________________

Chassis Type: 6N - VW Polo
16554 - Fuel Trim: Malfunction: Bank 1
P0170 - 35-10 - - - Intermittent

Chassis Type: 6N - VW Polo
16555 - Fuel Trim; Bank 1: System Too Lean
P0171 - 35-10 - - - Intermittent

Chassis Type: 6Y - Skoda Fabia
16555 - Fuel Trim: System Too Lean: Bank 1
P0171 - 35-10 - - - Intermittent

Chassis Type: 3B - VW Passat B5
16555 - Fuel Trim: System Too Lean: Bank 1
P0171 - 35-10 - - - Intermittent

Chassis Type: 9N - VW Polo
16555 - Fuel Trim; Bank 1
P0171 - 35-10 - System Too Lean - Intermittent

Chassis Type: Audi 3.2
16556 - Fuel Trim; Bank 1
P0172 - 35-10 - System Too Rich - Intermittent

Chassic type: Skoda Fabia  1,2l/4V 
16557 - Fuel Trim: Malfunction: Bank 2
P0173 - 35-10 - - - Intermittent

Chassis Type: 6N - VW Polo
16556 - Fuel Trim; Bank 1
P0172 - 35-10 - System Too Rich - Intermittent

Chassis Type: 3B - VW Passat B5
16556 - Fuel Trim; Bank 1
P0172 - 35-10 - System Too Rich - Intermittent

Chassis Type: 1J - VW G/J/B Mk4
16556 - Fuel Trim: System Too Rich: Bank 1
P0172 - 35-10 - - - Intermittent

Chassis Type: 9N - VW Polo
16556 - Fuel Trim: System Too Rich: Bank 1
P0172 - 35-10 - - - Intermittent

Chassis Type: 6N - VW Polo 
16556 - Fuel Trim; Bank 1
 P0172 - 35-10 - System Too Rich - Intermittent

Chassis Type: 8D - Audi A4 B5
16557 - Fuel Trim; Bank 2: system too lean
P0174 - System too Lean

Chassis Type: 4F0 - Audi A6 3.2L
16559 - Fuel Trim; Bank 2
P0175 - 007 - System Too Rich

Chassis Type: 4A - Audi 100/A6 C4
16559 - Fuel Trim: System Too Rich: Bank 2
P0175 - 35-00 - -
16556 - Fuel Trim: System Too Rich: Bank 1
P0172 - 35-10 - - - Intermittent
16557 - Fuel Trim: Malfunction: Bank 2
P0173 - 35-00 - -
16554 - Fuel Trim: Malfunction: Bank 1
P0170 - 35-10 - - - Intermittent

Chassis Type: 8D - Audi A4 B5
16554 - Fuel Trim; Bank 1: Malfunction
P0170 - 92-00 - Unknown Error Elaboration
16554 - Fuel Trim, Bank 1
P0173 - 92-00 - Unknown Error Elaboration
17658 - Fuel Level too Low

Audi A4 B5 96 a4 2.8l
16558 - P0174 - Fuel Trim, Bank 2
P0174  - System too Lean  -detecting lean fuel in exhaust
16555 -  Fuel Trim, Bank 1
P0171  - System too Lean -- detecting lean fuel in exhaust
16554   Malfunction
P0170 - 35-10 - - - reached maximum amount of fuel adjustment
16557 - Fuel Trim; Bank 2
P0173 - Malfunction

Fuel Trim: System Too Rich means / Rich Mixture implying too much fuel, not sufficient air
Fuel Trim: System Too Lean means / Lean Mixture, implying too much air, not sufficient fuel

Correct combustion relies on an air/fuel mixture of 14.7 to 1 ratio. Meaning 14.7 parts air to every 1 part of fuel, but if  the air ratio dips below 14.7 parts, then the mixture is called  "rich", whereas when the air exceeds 14.7 parts, then the mixture it is called  "lean".  To keep the engine running properly, the Engine Control Module measures the oxygen content in the exhaust emissions with the oxygen (O2) sensors in the exhaust system and makes adjustments to the mixture by injecting more or less fuel. The ECU is capable of keeping the STFT air/fuel mix within  specific parameters under normal conditions, and is based on input signals  from the Barometric Pressure Sensor and the Oxygen Sensor and will make minor adjustments to the air/fuel mixture. However when these adjustments it makes exceed a internally stored predetermined level, it sets  a fault code. When DTC P0171 and P0174 are triggered, the oxygen sensors are detecting too much oxygen in the exhaust fumes instructing the ECU to add more fuel in order to maintain a correct  air/fuel mixture.  But when DTC P0172 and P0173 are triggered the reverse is implemented. When DTC P0170 and P0173 are triggered the ECU is unable to compensate for the errors and uses an internally generate signal as compensation.  The main causes of STFT DTCs are due to leaking vacuum  hoses or a poorly functioning  Mass Air Flow Sensor sensing too little air or a faulty Barometric Pressure sensor or insufficient Fuel Pump pressure. Functionality of all these sensors can be checked by verifying there scan data before attempting to replace them. Cleaning the MAF wire with electro cleaner may help but take care not to damage it. Symptoms of STFT DTC may cause the EPC light to come on, make the car go into limp mode, stall, hesitate before acceleration, idle unevenly, backfire and refuse to idle. LTFT will be dealt with in future blog.

EPC HELP

EPC HELP Q & A

VW Beetle EPC problems. Audi EPC light, Audi Q7, Audi TT, car trouble, DTC, drive by wire, DTC memory, EPC, EPC dashboard light, EPC faults, EPC problem, accelerator pedal adaptation, Audi EPC Light problem, Audi Q7, audi TT, car trouble, crankshaft position sensor, drive by wire, dtc, DTC memory, EPC, EPC dashboard light, EPC faults, EPC problem, high pressure fuel pump, Limp Mode, throttle body, VW Beetle, wiring harness, O2 sensor,

Question?

My name is Lilian. I bought a 2001 Volkswagen Beetle a few months back. Now it loses power whenever that EPC light and check engine light switches on. Lately it happens more  often, so I switch it off and after a while start it again and it drives ok for only a few miles. I just cant go on like this, its upsetting to the point that I can cry. The VW Beetle club members say its the throttle body, so my friend replaced it for me.  It was really expensive from the agents so a got a used one from the junk yard. It fixed the problem, or rather so I thought because after about 200 miles the problem is starting again. Now I feel helpless. Pleeeez help me. Pleez Pleeez Pleez!

Answer!

Hi Lil sorry to hear about your troubles. As much as I would like to help you, you gave me way too little information to steer you in the right direction. A diagnostic scan of the VW would have really been helpful but since you don't have one, fixing it is going to mere guess work. EPC faults, can be solved by a process of elimination and since you replaced the throttle body and it lasted for 200 miles, without a problem, it is very likely that it was the throttle body that was faulty but the question is, did your friend do the adaptation so that the ECU can properly interface and control it? Sounds like this is your problem. You need to take it to a diagnostics equipt workshop to have the throttle body adaptation reset. I'm almost certain that would solve your problem.

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Question?

Me Zoe, I got Vw beetle, make power loss and make  EPC dashboard light on. I read  VW forum say was cause by brake light switch. I take my mechanic, he  say no fix, take  VW agents they recall VW Beetles with brake light switch problem. Me very lucky, VW agent replace it free but EPC problem no fix and now more worse. Happen every day. You me help. I you kiss.

 Answer!

Hello Zoe thank you, I am flattered that you want to kiss me. I have to tell you though, that the brake light switch has little to do with the EPC problem you are experiencing. The brake light normally has an influence on speedo-cruise and has nothing to do with EPC faults which are rather confined to the non-emission related components involved with fuel delivery and torque delivery. The variables are just too many to even guess what it could be. It could be one of many things that could be causing your problem. Even something as minor as a bit of dirt restraining your throttle control butterfly could cause a EPC problem.  Right now you problem could be anything from the crankshaft position sensor to the accelerator pedal position sensor. From your throttle body to the electrical connections, from your high pressure fuel pump to the ECU. I would suggest you have a  scan done then send it to me, perhaps we can try once again to define your EPC problem. I hope you understand my explanation. Cheers Zoe.

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Question?

Hola mi amigo, tengo un problema en el polo de mi mujer, y es que se queda al arrancarlo por la mañana del garaje o cuando esta una tarde entera como hoy en la calle que ya hace freskito, como si no subiese de revoluciones,como muy flojo, si le aceleras lo calas, o aveces hace pequeñas detonaciones por el escape, esto le dura unos 20 segundos y ya se espavila. Es un polo 1.4i 80cv, tiene 20milkm, y no ha tenido otro fallo. Posibilidades? 1º Yo creo que puede ser sensor de temperatura de inyeccion, aunque me funcione bien la abuja que mide la temperatura del agua?. 2º bobina? No se que mas podria ser, en dias normales, o si lo arrancas despues de 3 horas o 10 minutos ya va perfecto. Le meti el VAGCOM y no me dio ningun tipo de error. Espero vuestras respuestas

Answer!

Hola a ti. Primero quiero  decir, hablo espanol un poquito pero voy a probar ayudar. Sin error del VAGCOM es mas dificil decir. Apuesto a que es problema de encendido pero dudo es la bobina si le dura de problema porque es solo 20 segundos.  Posiblemente son los bujias o la RON de gasolina no es correcto o tienes agua en la gasolina. Pequeñas detonaciones por el escape no es normal especialmente baja 20milkm. ¿qué pasa con su recien garantía?

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Question?

Hello there, I hope you can shed some light on my problem, I'm having a mini crises with my Seat 1.8L Toledo. The EPC light came on yesterday, but when I turned the engine off and restarted, the EPC light went off and everything was fine until this morning. On my way to work  the car had a jerky/shudder and at that very moment the TC and EPC light came on and I lost power so that it would only rev to  2500 rpm. As a result I limped home them  I plugged in my VAGCOM. Very surprisingly there were no faults. So I decided to take the Toledo back on the road but when I turned on the ignition, the EPC/EM/TC lights came on. So once again I plugged  in my VAGCOM and the DTCs listed below was present. So I cleaned the Throttle Body and  checked the Throttle Body on group 060 and the adaptation field was showing 'ERROR'. What do I do now because I'm totally stuffed and need  a quick fix. Any light you can shed on this problem would be much appreciated.

VAGCOM: Chassis Type: 1M - Seat Leon/Toledo

Scan: 01 02 03 08 15 17 19 22 35 36 37 46 56

VIN: VSSZZZ1MZ3R1XXXXX Mileage: 164400km-102153miles

-------------------------------------------------------------------------------

Address 01: Engine Labels: 06A-906-032-AJQ.lbl

Part No: 06A 906 032 MJ

Component: 1.8L R4/5VT 01 0003 

Coding: 11510

Shop #: WSC 80179 

VSSZZZ1MZ3R1XXXXX SEZ7Z0C2XXXXX

4 Faults Found:

17967 - Throttle Body (J338): Fault in basic settings 

P1559 - 35-10 - - - Intermittent

17987 - Throttle Actuator (J338): Adaptation Not Started 

P1579 - 35-00 - - 

17579 - Angle Sensor 2 for Throttle Actuator (G188) Implausible Signal 

P1171 - 35-10 - - - Intermittent

17951 - Angle Sensor 1 for Throttle Actuator (G187): Signal too Small 

P1543 - 35-00 - - 

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Answer!

Hi Wayne, I'm glad to see that you uploaded your scan. Since the rest of your electronic modules have "No fault code found" beneath them, it essentially means that they are all OK. And seeing that you own a VAGCOM, I take it for granted that you may have had prior DTC which you erased. Erasing DTCs are OK but bear in mind that you also erase all values learnt by the ECU associated with your driving style including adaptation values.  The throttle body therefore needs to be re-adapted every time codes are cleared or control module  or battery power is disconnected. As the automatic adaptation software procedure runs, the control module learns the full range of throttle positions. So from what I can see above, the Idle Speed Control Throttle Position cannot be determined which could mean adaption needs to be done, or that the potentiometers in the throttle body may be near end of life. Overtime the slider wears through the carbon track so it makes intermittent contact and stymies the ECU. But before we condemn the throttle body, I need you to disconnect your battery at the earth terminal so that you can hard reset all the electronic modules. Make certain that the ignition is off  then reconnect the battery. Redo a scan and if all goes well, you will once again see your original 4 faults and 1  additional fault that looks something like "Supply Voltage Terminal 30: Signal Outside Specifications - attery/Generator supply faulty". This is absolutely normal because the ECU detected that the battery was disconnected. Plug in VAGCOM switch on the ignition but do not start the engine. Select VAGCOM 04-Basic Settings - which displays the Measuring Value Block screen. Select Measuring Value Block 060 (or 98) which displays the Basic Setting Value Block screen.  Channel 4 will display the word“Running” and other channels will display  the state of the throttle valve angle sensors but will change as the throttle is actuated by the ECM.  Please do not touch the throttle pedal nor turn  ignition key off during the adaptation because the throttle body adaptation relearn process is essential and may prevent the engine from starting if interrupted. If the adaptation was successful, Channel 4 will have changed from “Running” to “OK”. Display 3 would read "idle" and 1 & 2 display voltages levels, normally less than 5 Volts.  Logout, turn the ignition key off and wait about 1 minute seconds, to ensure that adaptation settings are saved then start the car. If however, it still shows "error" inspect the throttle body actuator connector contacts for damage or corrosion and make certain its contacts are secure then try to set adaptation again. If it still shows "error" clean the throttle body and check for wiring harness between the throttle body and the control module. Retry adaptation once again. As a last resort replace the throttle body because the potentiometers cannot be replaced as a separate item nor is it available for sale as a separate item. I hope this helps.

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 ...