Hello, I have a 2003 Jetta Wagon TDI with automatic transmission. Last week the car stalled on the highway and the engine light came on with the glow plug light flashing. I managed to get it started again and drive it to my local mechanic. He told me the codes he saw indicated it needed a new ECU. He wasn't really interested in finishing the job so I limped the car home. In searching online, I noticed that most people on the TDIClub website wrote that the ECU rarely failed. They recommended that I purchase the 109 relay, which sends information to the ECU and is often the culprit in these issues. I replaced the relay, but the car is still sick. It starts right up, but runs rich with a white smelly smoke the entire time it idles. Do you have any suggestions ? If I buy a used ECU, does it have to be an exact match ? I'd really rather not spend a whole lot of money on the car. It has almost 130K miles on it.Thanks - Steve
Welcome to Just Answer!!!First of all ecu are rare to fail like other have suggested , do you know which faults yo have triggering the glow plug light and possibly the check engine light ??
My mechanic did not give me the specific codes, and I don't have one of those vag-com tools. He only said that all the codes seemed to point to a bad ecu.
With the new relay it seems to run a bit better, but now it smokes more that before. Almost hard to breath around the car if there is no wind.
Can you get a hold of the tech to get these codes this is very important for the diagnosis process ??
I'll have to see if he wrote them down. Probably not.
Can you take any kind of guess at what it might be ?
You may have a faulty glow plug because the glow plug light but thats just a guess it would be better if i had the codes. I hope this helps.Feedback and bonuses are greatly appreciated thank you !!
I stopped at my mechanic's shop. He recalls the code being P0271. I checked a list posted on the tdi-forum for the glow plug light flashing, and this code was not there.
I also took it for a short ride yesteday. It runs, but puts out a lot of smoke. And now it has decided not to shift to the final overdrive gear. It tools around at 40 mph at 2500 rpm. It will also stall if it feels like it, but starts back up again if you wait a minute or so,.
Thanks - Steve
This fault is regarding cyl #4 injector you may be starving the engine for fuel thats why it runs like this have the mechanic check that cylinder injector you may just need a new injector . I hope this helps.
Thanks. Is this something I can check and change myself ?
If you have done it before if not then it may be a little hard without the correct tools because you will need to bleed the fuel system after replacement