Action in service
- If diagnostic fault code 'LIN bus communications: signal missing' is logged, start by repairing this problem, then clear the ECU fault memory, switch on the ignition, then wait at least 1 minute before checking to determine whether the fault has been logged again
- Check pump plug (also for corrosion)
- Check power-supply voltage to Terminal 30 / Terminal 31
- If no voltage is present, check the fuse - If the fuse is defective, replace it and check power supply for short and open circuits
- Check the LIN wire for opens and shorts to UBatt and ground
- Perform tester job, if not successful: Replace EWP electric water pump