Hi Geert,
The error code No. 198 is the Pump motor overheating.
As you mentioned " Pump motor is clean and not hot", so please check the following step by step:
1) There are 2 connectors located at the cover of the pump motor in which the 3 pins connector-X15 is the one used for To C sensor (Pin 01 & 03).
2) Unplug the X15 => to measure the resistant of To C to see if the value is around 500 - 700 Ohm => means that the To C is still OK. If not, it is faulty.
3) If the To C is still OK, but the error code 198 still occurs means that the wiring harness is cut off somewhere from the Pump motor converter (2U03) to the motor (X15). In which :
- X15:01 => connected to X150:07 (2U03)
- X15:03 => connected to X150:04 (2U03)
If you couldn't find out where the cutting point is, you can make the bridge from :
- X15:01 => connected to X150:07 (2U03)
- X15:03 => connected to X150:04 (2U03)
The test the truck to see if it is OK
PS: By the way, the pump motor and drive motor are all using the same type of To C - Part No is 0156234. Therefore, you can switch over to test just in case.