Golf IV TDI: No Gas Pedal Response?

"I'm experiencing issues with the throttle response on my Golf IV TDI 90 hp. The engine suddenly stalls while driving. The accelerator pedal only responds again after turning the ignition off and on. The throttle position sensor has already been replaced, but the error code "throttle position sensor" is still being read."
After I refueled with a better grade of diesel, the error initially disappeared, but it has now reappeared multiple times.
Furthermore, the car didn't reach its full performance today (only 160 km/h instead of 180 km/h).
What could be the cause of the problem? Could it be the engine control unit?

Does anyone have any ideas?

Regards,

Simon.

Hi,

Are there any faults in the wiring harness or at the connectors?

Best regards, Rainer.

I have been dealing with the same problem for 2.5 years .

Hi, have you checked the 109 relay? These things are often responsible for many problems in TDI engines.

Sure, here is the translation of the text from German to English:

'Hello'

Guys!!

Think very carefully.

If the accelerator pedal sensor is detected as defective, how can diesel fuel help?
If the 109 makes noise, the engine will also not idle properly because, in that case, the control unit is completely switched off.

I consider loose connections or worn spots in the plugs and cables to be a much more likely cause.

m;

Regarding that topic again, I myself had a similar problem with the relay. The engine started normally, but while driving, it suddenly stopped responding to the accelerator, the engine then turned off and restarted. After a long search, it turned out to be a cold solder joint on the relay, which sometimes made contact due to vibrations and sometimes didn't. Please take a closer look at the relay; if it still has a white cap, replace it, as the new ones are gray.
Sure, here is the translation of the text from German to English:

'Hello'

Yes, error code 109 is well-known as a cause of problems, as the search results indicate.

But none of the symptoms really seem to fit the 109.

- the idle speed when no throttle is applied (the 109 would not idle, but would instead "turn off").
- 160 km/h instead of 180 km/h at full throttle (this limitation can only occur with the 109 model under very specific conditions, as the engine control unit modulates the pulse width to turn the motor on and off!).

m;

I haven't encountered a pulse-width modulated relay or power supply in this area yet, but let's try something new .

I think that if it were really making such strange noises, there would already be an error stored in the control unit .

'If necessary, enter 'control unit defective'.'

vagtuning wrote:

I haven't come across a pulse-width modulated relay or power supply in this area yet, but let's try something new . I think that if it were really making such strange noises, there would already be an error stored in the control unit . If necessary, enter "control unit defective"

.

As I mentioned before, I now have two new control units installed, and the error is still there. I am waiting for my last repair appointment.

The exact error code, including the number and text description, would certainly be helpful.

Was wurde ersetzt: der Geber oder das Steuergerät?
What remains... I would say plugs, connectors, and cables?

K@pu should really decide on a thread, because he probably means "his" thread here: https://community.dieselschrauber.org/en/viewtopic.php?t=10672
"I'd put my money on the faulty wiring harness... Is that what's meant by the 'last repair date'?"

In this thread, the original poster seems to have unfortunately left...

pschaefer wrote:

K@pu should really decide on a thread, because he probably means "his" thread here: https://community.dieselschrauber.org/en/viewtopic.php?t=10672 "I'd put my money on the faulty wiring harness... Is that definitely what's meant by the 'last repair date'?" In this thread, the original poster seems to have unfortunately left...

I have to say that the last time this wiring harness was retrofitted, and as described, the fault reappeared after about three-quarters of a year.
Best regards,

/PS: I've decided to describe my repair experience in a separate thread, so I'll be posting it a bit later.

And what?! Are there still errors? I know this problem, I've had it too. Turn the ignition off, then on again, and it works again. But then the intervals get shorter and shorter until it stops working completely. Then you have to let it cool down, and it starts the same process all over again. The cables in the wiring harness then become black on the inside and absorb moisture. Since the accelerator pedal sensor is a safety-critical component, the safety thresholds are very low. Replace the cables and it's fixed. Get a wiring diagram, cut the cables at the T68 and at the accelerator pedal sensor, reroute them, and reconnect them. That's it.

I've just been looking into the issue with the gas readings.
I cannot offer a solution to that, but I would like to present a similar problem here.
"On my TDI PD (ATD) engine, I sometimes experience a situation where it suddenly stops responding to the accelerator pedal when the load changes. After briefly releasing the pedal and then pressing it again, everything returns to normal, and I don't need to restart the engine."
Since this doesn't happen very often, I haven't yet had the opportunity to define specific situations or states (e.g., full tank, empty tank; high or low speed, etc.) for this purpose.
Perhaps someone knows a quick answer?
Best regards, Hoin.

It could be the brake pedal switch! If you keep your foot on the accelerator and then press the brake with your other foot, it immediately goes to zero. Then you have to release the accelerator and press it again before it gives you gas again. Maybe someone should take a look at that.