I have a 150 BHP VRS (Engine code - AUM) without any modifications.

For the past 2 months my vrs has been running rough at idle. And it has gone from bad to worse in the last 2 weeks as it has become impossible to drive. The local Skoda dealer point recommended changing the Throttle Body. I got second and third opinions from other service centers to change TB. So last week the Skoda dealer changed the TB. The sad part is that didnt fix the problem. The engine is still running rough at idle, there is huge RPM fluctuation, no accelerator response. To top it all, the engine dies while starting if I dont press accelerator. So dropped the vehicle back with the dealer and they have been trying to identify the issue for last 3 weeks without any success. They have checked the wiring and changed some sensors (dont know which sensors) too. But nothing has helped so far.

I just heard that they have asked for technical help from Skoda (factory i believe).

The scan report at dealer point produced the following errors:

17579 - Angle Sens -2- for thr. drive -G188-unplausible signal

17705 - Connection charger-throttle valve Pressure drop

17950 - Angle sensor -1- for throttle drive -G187- Unplausible signal

17953 - Throttle valve control system malfunction

17987 - Throtle valve control unit -J338- Adaptation not started

18010 - Voltage supply - terminal 30 Voltage too low

18012 - Control unit faulty - Sporadic fault

Any suggestions or ideas on to solve these errors?

Regards

Ram

Well, I know those errors make me think of the throttle body, the throttle valve potentiometer (measures actual throttle opening) and the throttle position sensor (measures requested throttle opening at pedal). There's also an outside possibility of a break in one of the relevant wires, but that really wants a good auto electrician to diagnose.

Sounds like you have a vacuum leak ( split hose) very common, also looks like your battery is low.

I'd put my money on the coolant temp sensor being at fault. The symptoms you describe are classic for CTS failure.

If they changed the throttle body without disconnecting the battery it would throw a bunch of implausible signal codes.

Thanks for the suggestions. The workshop was off yesterday due to a local holiday. I will relay these suggestions to the mechanic. I should have some news today.

One thing that baffles me is you say you have a 150bhp AUM VRS! Mk1 VRS has a 180bhp AUQ engine.

One thing that baffles me is you say you have a 150bhp AUM VRS! Mk1 VRS has a 180bhp AUQ engine.

Wasn't there a 150bhp version somewhere abroad (ie. not in the UK)?

Yes, the version sold in India was 150bhp.

You are right. The Mk1 VRS sold in India is 150 BHP and engine code is AUM. In fact, Skoda launched Mk2 VRS yesterday and it is 160 BHP. They have different strategies for each country it seems.

Update on my car. I went to the workshop to find that they are yet to send the report to Skoda. I didnt want to wait for another 3 days so insisted them to replace CTS and deliver the vehicle. They were reluctant at first but they gave in eventually. After the change the engine is running smooth and have not witnessed any hunting. I hope it stays the same. I am going to check the battery later today and replace it if necessary. If the issue comes back, I will check for any vaccum leaks.

Thanks for all your suggestions.

You are right. The Mk1 VRS sold in India is 150 BHP and engine code is AUM. In fact, Skoda launched Mk2 VRS yesterday and it is 160 BHP. They have different strategies for each country it seems.

Update on my car. I went to the workshop to find that they are yet to send the report to Skoda. I didnt want to wait for another 3 days so insisted them to replace CTS and deliver the vehicle. They were reluctant at first but they gave in eventually. After the change the engine is running smooth and have not witnessed any hunting. I hope it stays the same. I am going to check the battery later today and replace it if necessary. If the issue comes back, I will check for any vaccum leaks.

Thanks for all your suggestions.

Glad you got it sorted.

The battery code you had is just the ecu recognizing that at some point the battery has been disconnected.

Yes, the version sold in India was 150bhp.

Down to the fuel quality iirc

I tested the battery and found that it was on its way down. So changed it. Now I could find a marked difference while starting the car.

I have driven close to 150 KMs after changing CTS and battery and everything looked fine till this morning. While driving to office, I felt flat spots (loss of power) at times while accelerating and decelerating. Though did not affect driveability, its annoying. Thanks to peak hour traffic I could not test it on a open road.

I ran the car through the generic OBD2 scanner (Bosch KTS501) and found the same set of errors from first post. Cleared the errors and tried doing TB adoptation. But it would not happen and KTS kept throwing "Adoptation error". Went back to the error memory and got these 2 errors.

17987 - Throtle valve control unit -J338- Adaptation not started

18012 - Control unit faulty - Sporadic fault

Could it be that the TB changed by the dealer is faulty? Or is it a problem with ECM? Any suggestions please...

Edited 5 September, 201114 yr by rammkp