Volvo All Engines (2004 Emissions) Fault Code: PPID 122 FMI 4 Engine Compression Brake

Fault Condition: This fault can only be detected if the engine brake is demanded ON. If the fault clears, the compression brake system will not be enabled until the power is cycled.
The engine brake must be operated to ensure the fault has been cleared. The engine brake can only be operated with the engine oil temperature above 131ºF (55ºC), the vehicle moving and the engine speed above 1200rpm.

FMI 4 indicates there is a short circuit to ground in the Engine Compression Brake Solenoid control circuit.

Possible repairs:

Turn the ignition key OFF first.

1) If code PPID 122 is not set, wiggle the harness and connectors to try to set the code. Visually inspect the EMS Module harness connector and wires for frayed or loose connections.
2) Disconnect the Engine Management System (EMS) Module connector B. Measure the voltage between the EMS Module connector B pin 30 and a good ground. If voltage is present, the control line circuit is shorted to voltage. Locate the short to voltage, repair the circuit and retest the system. If there is NO voltage present, verify the diagnostic code, the FMI and retest the system. If the FMI 3 is still active, replace the EMS Module and retest the system.
3) Disconnect the Engine Management System (EMS) Module connector B. Disconnect the Engine Compression Brake Solenoid. Check for continuity between the EMS Module connector B pin 30 and a good ground.
If continuity exists to ground, replace the Engine Compression Brake Solenoid or locate and repair the short circuit to ground. If there is NO continuity, verify the diagnostic code, the FMI and retest the system. If the FMI 4 is still active, replace the EMS Module and retest the system.
4) Disconnect the Engine Management System (EMS) Module connector B. Disconnect the Engine Compression Brake Solenoid. Check for continuity between the EMS Module connector B pin 30 and Engine
Compression Brake Solenoid connector pin 1. If there is NO continuity, repair the circuit between the EMS Module and the Engine Compression Brake Solenoid.
5) Disconnect the Engine Compression Brake Solenoid. Check for continuity between the Engine Compression Brake Solenoid connector pin 2 and fuse 43 (ENG COMPT # 1) connector B. If there is NO continuity, replace the Engine Compression Brake Solenoid or repair the circuit between the fuse 43 and the Engine Compression Brake Solenoid.
6) Disconnect the Engine Management System (EMS) Module connectors A and B. Visually inspect EMS Module connectors for dirt, loose pins or deformed contacts. If a repairable open is found or the terminal feels loose, repair the harness connector. If the test lead is making good contact with the connector terminal, verify the diagnostic code, the FMI and retest the system. If the FMI 5 is still active, replace the EMS Module and retest the system.