zszabo

I went back to my car and I managed to start it, but it ran a bit rough. I was able to start the engine and rev it and even though the idle wasn't completely smooth, it was much better than last night.

I also managed to drive the car around and it seemed to be OK.

I ran a throttle body adjustment and connected the VAG to see what was wrong. Here are the codes that I received:

Address 01: Engine
Controller: 4B0 906 018 CH
Component: 1.8L R4/5VT G 0002
Coding: 16201
Shop #: WSC 63351
6 Faults Found:
17976 - Throttle Actuator (J338): Mechanical Failure
P1568 - 35-10 - - - Intermittent
17972 - Throttle Actuator (J338): Under-Voltage during Basic Setting
P1564 - 35-10 - - - Intermittent
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
17579 - Angle Sensor 2 for Throttle Actuator (G188) Implausible Signal
P1171 - 35-10 - - - Intermittent
17950 - Angle Sensor 1 for Throttle Actuator (G187): Implausible Signal
P1542 - 35-10 - - - Intermittent
17976 - Throttle Actuator (J338): Mechanical Failure
P1568 - 35-10 - - - Intermittent
Readiness: 0010 1101


Since the car ran OK, I decided to drive it around the neighborhood for a bit (I figured it's better to try it now during the day than later at night when all towing companies are busy pulling drunk drivers off the streets). I went to a shopping center about 10 minutes from my house and got lunch - and when I got back, the problem came back. I tried a TBA but that had no effect; so I ended up getting the car towed to my house.

It looks like my internet connection is better than before so I'll search the archives. In the mean time, has anyone seen those error codes before? Should I try cleaning the TB or is it most likely toast? I'll be looking through bentleys etc. but if someone has any advice to offer in the mean time, please let me know. Thanks!

RKA

Can you look over the wiring harness that connects to the throttle body? Any broken wires or loose connections? Short of that, I would *guess* the throttle body requires replacement. It really does seem like a simple electrical issue though...especially since it is intermittent.

zszabo

I just started it again and it's running ok once again.

Are you talking about the wire that connects to the TB? Are there any other ones beside that (I'll check both ends)? Perhaps this is a heat related issue after all, it seems like it runs ok for a bit when the car is cold, but then starts malfunctioning as it heats up.

RKA

Yup, there is a wiring harness that connects to the TB.

zszabo

Both of them disappear underneath the manifold and I assume they connect directly to the ECU box.

Should I try reseating the ECU harnesses? I unplugged both wires mentioned above, they both looked OK. I can't obviously test their conductivity, since I can only access one end (I assume the other end connects directly to one of the ECU harnesses?).

After I reconnected the wires, I idled the car for a bit and revved the engine. Nothing seems wrong at this point; but I suspect once I drive it around, the same thing will happen eventually.

I'm going to try and reseat the ECU harnesses, clear the codes, run another TBA, and then VAG the car for codes. Beyond that, I'm not sure what else I can try at this point. Either the TB is on its way out and it starts failing as it heats up, or there's another electrical component that has become overly sensitive to heat.