Niki Georgiev

Hello fellas, I have a strange problem with my A8 4h 4.2. When I drive my car for few minutes (up to 1h) I get a yellow signals on the screen. I went to my garage and checked the error - P2637. I managed to remove the error with the VAGCOM but after few minutes of driving same thing happened. I went to some mechanics but nobody gave me the correct answer or any answer.... Can somebody help me with more information about this problem and how to fix it. Thank you.

Niki Georgiev

I dont know how to edit my post and sorry for the double one, but I want to give you more information: The car is 2011 and I am from Bulgaria. The car is imported by a car dealer and I cant tell you exactly from where but must be Germany or Italy. We checked the wire connections and they looks pretty good. Visited 4 mechanics to scan the error but nobody could give us any answer. Only one of them told us that there is a problem with ABS sensor and we replaced it, but for nothing. After 20 minutes of driving same thing happened. From the information I found on internet the possible issues could be:

• (PCM) failure
• Transmission Control Module (TCM) failure
• Wiring issue
• Mass airflow senser
• Vacuum leaks.

For me its not possible to buy all of this new and test it and Its really hard to find these parts used in Bulgaria. Also the used ones could be broken too. The only thing I need from you guys is to tell me where to search or give me more info. The mechanics here only wants to take our money and do nothing. I dont want to leave my car in any garage and ppl do experiments with it. Thank you.

MP4.2+6.0

Welcome. Your car is a D4 version rather than the older D3 for this forum, but maybe we can help. A guess is that you have the in wheel sensor type TPMS system. For the D4 it varies by market and engine, and in the USA we generally have the simpler indirect system that no longer has in wheel sensors. The D3 did have the in wheel sensors, so folks on this forum are familiar with them.

Look at your tire valve stems at each wheel. If they are a simple black rubber stem like many car tires, you have the indirect sensor type and my guess will not apply--unless a prior owner or shop didn't re fit the correct equipment. If instead you find what looks more like a metal valve stem (it is actually painted plastic) and a round base with a nut area for a wrench on the top, it is the in wheel sensor type. If it is the in wheel type, you probably have a screen in the MMI that shows tire pressures and temperatures. If it is this in wheel type, your issue is most likely basic: one or more of your sensors is far the end of its life. They have batteries internally that cannot be replaced, so you replace the whole sensor (inside the wheel) instead. Average battery and sensor life for D3's is 6 to 61/2 years, so for a 2011 you would be right on schedule to have issues. For D3's there are cheaper aftermarket ones; the dealer ones are somewhat pricy. You should replace all of them (including spare if so equipped) or you will just chase the same issue as each one starts dying. Best time is when/if you need new tires anyway, since tire has to come off to replace the sensor. Only 5 minutes or so to do it once tire is off, and any tire shop is familiar with them now.

BTW, was it really VAG-COM (VCDS)? A guess is it was the cheap engine OBDII scanners. And cheap scanner means likely bad data here. It only scans the engine computer, which has only basic codes for many things that may be controlled by other on board computerized modules A "real VCDS" will scan all the modules, including one for TPMS that will be there if it has the direct TPMS system. Instead we--and the mechanics--will be guessing. Also it was probably why one guessed hit may be an ABS sensor. The simpler TPMS system uses those ABS sensors to estimate tire pressure issues or leaks. Be sure in any case you have access to shop equipment to give you an accurate assessment of the issue--or we guess and you spend money on unneeded parts and labor.

chudlin

when i had issues with the ones on my D3 i just went into vcds and turned the damn thing off! its not a feature im fussed about if im honest

Niki Georgiev

New info:

The car is US version. It doesnt have tire pressure sensor. I ran the car today for 10 minutes w/o touching the brake and the error came again. I also let the car working on neutral for 30 minutes and error came again. I guess the error is not related to the ABS. If the weather is hotter, the error comes faster.

P.S. I cant let the car running like that bcs this error makes the car works bad.

chudlin

Considering that the tpm system is for tyres and not the ABS, one would assume that it has nothing to do with the ABS...

2. the TPM system will not hinder performance, it is purely a monitoring system. the only performance degradation youll see is that the system is working correctly and your tires are low. try filling them?? what are your tyre pressures? have you manually checked them with a gauge?

3.if you dont want the tpms, you could always have someone with vcds turn it off. then itll just go away, but it wont solve the issue of it working. itll just stop the notifications

Niki Georgiev

Today The errors appeared on the screen when I was driving at the town and after I get on the highway the errors disappeared. I was still able to see the error on the computer but not on the screen. The problem comes from the heat for sure... When the car is cold in the morning it takes longer time for the error to appear. When the car stays under the sun the whole day it takes just a 5 minutes. Which sensor can works bad due to high temperatures? Y-day i got a warning to replace the battery. I ordered an original AGM so we will see.

Niki Georgiev

Hello, I dont see my last post so I will repost it and add some additional info.

Several days ago i got a warning to change the battery. I ordered a new OEM battery and replaced it. After that drove the car a whole day w/o any problem and when I was going to write you guys that my problem is fixed ... baaam.... same errors. I dont know why it took so much time to appear but now is like before. I had a hour for audi service for y-day. I went there and guess what... They cant tell me whats the problem and the only thing they can do is to start changing parts and sensors and check whats wrong and whats not, but I have to pay for all the parts they tried and for the work they put on it. The problem is that I dont like the idea to spent my money for a "lottery". Also the work and parts from audi are really really over priced. The only information they could give me is that "pump-regulators for high pressure" are gone due the bigger octane in european fuels and they let gasoline go into the oil. I hope you understand me. I will attach a picture of them bellow. The problem is that i dont think so. The oil level is still the same and I cant smell the gasoline. Also I dont know how this error can appear and clear by itself.
I think that this error P2637 is caused by other ones in the engine section.