AXR T3: Jerky Acceleration - Troubleshooting Guide

Hello.


As soon as I press the accelerator, the engine speed increases, but with a lot of jerking. Between 2,000 and 3,000 RPM, it runs relatively normally. Also, it's smoking like a blast furnace. There are no error codes in the engine control unit or the speedometer. The mass airflow sensor is working correctly, and the throttle position sensor signal is correct. The only sensor that's showing an error is the oil sensor, and the indicator light in the dashboard is flashing.
Can someone help me with that?

Quote:

the indicator light in the switchboard enclosure is blinking

.
Then there should be something in the error memory. -> Grab a VAG-COM device and read the error codes.

So, I tried something out.
1. Installed and connected a new LMM (lambda sensor): Car is shaking and smoking.
2. Mass air flow sensor (MAF) connector disconnected: The car runs and responds normally to acceleration.
3. LMM connected but disabled: The car still jerks and smokes, but significantly less.

...and now what???

Memory error. Oil sensor short circuit.

Loose connection to the mass airflow sensor (MAF sensor).

I once had that at ASV.
- drive normally.
- Accelerate normally.
- richtig drauflatschen ... Rodeo.

"The reason was that when the cable was pulled forcefully, it moved in a way that it lost contact with the mass airflow sensor (MAF), causing brief interruptions in the airflow."

as noted.

Colleagues are hitting it, and I'm logging in from the passenger seat.

Solution: Re-establish connection - unplug it from us, plug it back in, and you're done.

m;

Problem found.
'Error code indicates 'Brake pedal sensor signal is implausible'.'
This causes the throttle valve to close, and all the exhaust gases are forced through the recirculation system.
I've tried everything already, but I can't get rid of this error. The signals are reaching the control unit correctly. I've even measured them directly at the 120-pin connector. What else could be causing this error?
Also, the throttle valve motor is constantly beeping when the ignition is on. Is that normal?

Regarding the brake pedal switch issue: didn't we just have this problem yesterday or the day before?
-> Search

I found something in the 'search' function, and it says that this error occurs when both brake lights are defective. My brake lights are still connected to the original wiring harness. I've studied the wiring diagram for the Golf 4, but I can't find anywhere the control signal for the brake lights. Or are they normally controlled by the ABS/ASR control unit? Does anyone have a wiring diagram for the brake lights?

Hello everyone,

What type of brake pedal switch did you use? I'm asking because the TDI requires two signals (normally open and normally closed). The slopes of both signals must be perfectly aligned, otherwise the signal will be unreliable.

For my T3, I installed a brake pedal switch from a Sharan.

If you need more information, feel free to contact me.

Best regards, Gunnar.

I solved the problem.
I connected the dual switch to the control unit, but I continued to run the brake lights through the original wiring. This resulted in a voltage of 8.9V coming from the control unit out , which is considered normal according to Bosch. Since the high level for a control unit is defined as 8-15V, it was always present, regardless of whether the switch was activated or not. Only when you create a connection, as is originally done in the Golf, from the brake lights to ground, is the potential pulled down to 0V. In the wiring diagram for engine electronics and basic equipment: wiring connection A118.

Best, Mike.
'Now I've exceeded the 'boost pressure limit', and it's also shaking violently even without the turbo engaged. I'm going to take a look at the fuel supply.'

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