Group 28 Troubleshooting MID 128 PPID 122 Engine Compression Brake 34 Type of fault FMI Description: Fault Condition: Possible Symptoms:
Possible Cause FMI 1 • Data valid but above normal operational range • Below range • No Volvo Compression Brake (VCB) • Low engine oil temperature FMI 3 • Voltage above normal or shorted to high source • Short Circuit + • Volvo Compression Brake (VCB) can not be turned on • Engine brake function derated • Gear shift performance derated for some automatic transmission boxes • Faulty Volvo Compression Brake (VCB) actuator • Faulty harness FMI 4 • Voltage below normal or shorted low • Short Circuit - • Volvo Compression Brake (VCB) can not be turned off • Engine stops running • Engine impossible to restart • Faulty Volvo Compression Brake (VCB) actuator • Faulty harness FMI 5 • Current below normal or open circuit • Open Circuit • Volvo Compression Brake (VCB) can not be turned on • Engine brake function derated • Gear shift performance derated for some automatic transmission boxes • Faulty Volvo Compression Brake (VCB) actuator • Faulty harness