Hello!

I was already on such cases (OM-Pimespo)
The key-switch was the problem. The DC/DC converter power supply was missing.

I think, first check the voltages:
- Check the power supply
-Check the DC/DC converter!! (Power supply from the keyswitch.
-Check the CAN_BUS: -Resistance measurement
If one of the CAN bus leads, CAN high or CAN low
is interrupted, this can be measured with a resistance
measurement when the truck is switched
off:
1. Resistance measurement
Correct value: 60 ohm
One lead interrupted:
120 ohm.

2. Voltage measurement CAN high
to GND
Correct value: > 2.5V <3.5V

3. Voltage measurement CAN low
to GND
Correct value: < 2.5V >1.5V

I can send a repair manual (OM-Pimespo version)


FE12, Internal buffer battery of the FPS is discharged
The operating hours cannot be stored after key-operated switch OFF/ON. As a result, the
currently last stored value is displayed. A save routine is performed appr. every 5 minutes.
The hours-run counter therefore operates with a slight degree of imprecision during
operation. Exchange the FPS / internal back-up battery (possible after expiry of the guarantee
period of FPS).