Leistungsmangel A4 2.5 TDI BDG | Posts 16+

christians wrote:

This means a long delay when suddenly accelerating.

I blame the LD (Low-Density) setting, as it seems to be causing some distortion. "When mine does that and has a late LD build-up, it feels similar. 'Unfortunately,' everything seems okay in your logs, since it's always injecting the full amount..."

Herr Antje wrote:

christians wrote: That means a long delay when you suddenly press the accelerator. I blame the LD (Low-Density) setting, as it seems to be causing some distortion. If mine does that and has a late LD build-up, it feels similar. "Unfortunately," everything is okay in your logs, since it always injects the full amount...

Mr. Antje, have you ever replaced the load cell sensor? I once read that they sometimes malfunction, which can cause the motors to not run properly. I wanted to swap it out (in the AFB) before, but I was too lazy because it's not easy to get to.

mserge wrote:

Mr. Antje, have you ever replaced the load cell sensor?

Yes, I've gone through the entire process and now I know that the problem is mainly due to the vacuum. The sensor is really difficult to reach, and mine was still working well, so unfortunately, it was all for nothing. Thank you for the tip!

Hello,

I'm bringing this thread back up because something new has come up in the meantime.

For some time, I've been experiencing a rather uneven idle. The values for the idle speed control were elevated in 2 cylinders (approximately 1.2 / 1.5 mg/H).

During the last service, the workshop foreman confirmed that it appeared one of the cylinders was misfiring.
They then began to troubleshoot the problem.
There is likely a documentation available from VAG regarding this problem: 'lack of fuel pressure in a warm engine.'
According to the workshop foreman, the control unit itself was the cause of the problem, and I received a new control unit. The idle is back to normal, and the engine is running better.

I'm not entirely sure yet if this has resolved all the issues. When I have time, I'll run another log test to see if any values have changed.
The idle values, however, appear to be back to normal as expected.

Best regards, Jean.

Was was the control unit referring to? Was it the engine control unit?
Do you know more about the technical information (TPL number)?

Could it perhaps be the ESP control unit instead? How could the engine control unit regulate the fuel injection pressure?

To the best of my knowledge, the ESP controls the pressure, not the MSG.

Or what?

The internal pump pressure is controlled solely by a mechanical valve, while the injection pressure is determined by parameters such as speed, duration, type, and condition of the ESP (Electric Submersible Pump) and ESD (Emergency Shutdown system). Nothing in that system is controlled by any control unit.
It's just that you can't simply replace the pump control unit, which is why I suspect it's the MSG (Main System Module).