Passat TDI ATJ: No Power? Troubleshooting Guide

Guest Free account, no CAN development support

Hello everyone,

'For the past two days, my Passat has had no power. It only revs above 3000 RPM when going downhill or when stationary. To clarify, I replaced the mass airflow sensor (MAF sensor) two weeks ago. I repeatedly had a 'MAF sensor short circuit to ground' error in the error memory. Since I had an old MAF sensor, I temporarily installed it. This resolved the short circuit issue, but the performance wasn't optimal with that MAF sensor, so I had already planned to buy a new one.'

Okay, no more performance for now. I've done a diagnostic run with VAG-COM, see the attached file. If the selected parameters are not okay, please don't get angry with me, just tell me what I need to change, and I'll do another test run. I've noticed in the data that the mass airflow and boost pressure are hardly changing, and that's a bit concerning to me.

I continued searching, as best as I could in the dim light, and I found that the small rubber hose connected to the air filter housing had come loose. I reattached it, but there was no improvement.

Do you have any other ideas?

Best regards,
Stefan.

Translated on 27-09-2026, 2:59.

Check if the diesel filter is still allowing enough fuel to pass through, or replace it as a precaution.
The MWB 013 and 023 readings provide information about this. If these readings show catastrophic values, it usually means the engine is not receiving enough fuel, rather than the PDE (fuel injection pump) being defective.

Translated on 27-09-2026, 2:59.

Hi,

Mass air flow sensor reading is much too low. Check the new mass air flow sensor and its connections.
Otherwise, investigate the cause of insufficient airflow.

Best regards, Rainer.

Guest Free account, no CAN development support

Mass air flow sensor reading is much too low. Check the new mass air flow sensor and its connections.
Otherwise, investigate the cause of insufficient airflow.

Hello Rainer,

LMM (mass airflow sensor) replaced, and while doing so, the attached corrugated hose for the VTG (variable turbine geometry) was also replaced. Now it's running like it did before.

Best regards,
Stefan.