Idle speed control for the 2.5 TDI BDH engine

Hello everyone,

Unfortunately, I've noticed that my BDH 2.5 TDI is starting a bit poorly. I've tested the coolant temperature sensor, and it seems to be working fine. The spark plugs are also new.
The engine looks quite good through the oil filler cap opening. The engine runs smoothly and pulls cleanly.
Could you tell me something about idle speed control? What exactly do the negative signs mean?
The mileage is documented as 212,000 km. Year of manufacture: 2004.
The measurements were taken with the engine running warm.
Thank you.

Hello,

When there is a negative injection quantity correction, the corresponding cylinder must inject less fuel in order to achieve a constant angular velocity at the crankshaft.

Since all the cylinders are showing negative values, cylinder 2 (the reference cylinder) is likely the problem, as it requires more fuel injection. The sum of all correction factors is 0.

I can't imagine the engine is running smoothly, but you're standing in front of the car and you have to think it's okay. Possibly. Upload video here?

If you see a need for action:
- Check the camshaft and rocker arms.
- Check compression.
- Check the nozzle holder assembly.

... would proceed in this order.

Best regards, Rainer.