VP37 & Quantity Setting - Emergency Program

Hello.

I've had a customer's ALH vehicle in the workshop for two weeks.
Two error codes are displayed.
- 17970 Quantity setting, upper limit value.
- 17971 Quantity setting, lower limit.

The diesel filter was clogged, and the quantity adjuster was stiff.

I've now replaced the metering unit with a used one from an AHF, and also the distributor head (the metering sleeve and distributor piston were sticking).

Now everything moves smoothly as it should, but the problems keep recurring.
Meanwhile, I have increased the error limits from +/- 0.514 volts to +/- 10 volts, but still no improvement.

Both errors cannot be cleared in the low-range mode, even though there is no monitoring of the injection timing. The engine runs smoothly without misfires and has power. The pump voltage is approximately 1.6 volts at 4.4 mg in the low-range mode when the engine is warm.
I've noticed that the designated quantity control valve, when tested without a pump, doesn't produce any errors.

"Does anyone have any other ideas? Adjusting the reference ring probably won't make much difference if both the upper and lower limits aren't being reached according to the control unit. However, when you run the actuator test, you can see that the limits are definitely being reached."

Hello,

Am I understanding correctly that if you look at the values for the lower and upper limits in the corresponding measurement block (19), everything seems correct, but the errors still appear?

Have you already tried importing the original data, or is this the original data?

Best regards, Rainer.

Hi Rainer,

"Thanks, I forgot about that... it's been ages since I worked on VP37 engines."
There was a positive offset in both measurements. I have now adjusted the reference ring to a more positive value, and it is now running without errors .

Thank you very much!