Tech Tips
Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table.
Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
| Symptom | Suspected Area | Link |
|---|---|---|
| Engine does not crank (does not start) | Starter | |
| Starter relay | ||
| Starter signal circuit | ||
| VC output circuit | ||
| No initial combustion (does not start) | ECM power source circuit | |
| Pre-heating control circuit | ||
| Compression | ||
| ECM | ||
| Fuel injection pump | ||
| VC output circuit | ||
| Engine immobiliser system | ||
| Difficult to start (cold engine) | Starter signal circuit | |
| Pre-heating control circuit | ||
| ECM | ||
| Fuel injection pump | ||
| Engine coolant temperature sensor | ||
| Fuel injection nozzle | ||
| Fuel filter element assembly (level warning switch) | ||
| Diesel throttle body | ||
| Difficult to start (hot engine) | Starter signal circuit | |
| ECM | ||
| Fuel injection pump | ||
| Fuel injection nozzle | ||
| Fuel filter element assembly (level warning switch) | ||
| Diesel throttle body | ||
| Engine stall (soon after starting) | ECM | |
| Fuel injection pump | ||
| Fuel filter element assembly (level warning switch) | ||
| Diesel throttle body | ||
| Engine stall (other) | ECM power source circuit | |
| ECM | ||
| Fuel injection pump | ||
| Diesel throttle body | ||
| Incorrect first idle (poor idling) | ECM | |
| Fuel injection pump | ||
| Engine coolant temperature sensor | ||
| Fuel filter element assembly (level warning switch) | ||
| High engine idle speed (poor idling) | ECM | |
| Fuel injection pump | ||
| Engine coolant temperature sensor | ||
| Air conditioning signal circuit | ||
| Low engine idle speed (poor idling) | Compression | |
| ECM | ||
| Fuel injection pump | ||
| Engine coolant temperature sensor | ||
| Fuel injection nozzle | ||
| Diesel throttle body | ||
| Air conditioning signal circuit | ||
| Valve clearance | ||
| Fuel line (air bleed) | ||
| Rough idling (poor idling) | Pre-heating control circuit | |
| Compression | ||
| ECM | ||
| Fuel injection pump | ||
| Fuel injection nozzle | ||
| Diesel throttle body | ||
| Valve clearance | ||
| Fuel line (air bleed) | ||
| Hunting when engine is hot (poor idling) | ECM power source circuit | |
| Compression | ||
| ECM | ||
| Fuel injection pump | ||
| Fuel injection nozzle | ||
| Valve clearance | ||
| Fuel line (air bleed) | ||
| Hunting when engine is cold (poor idling) | ECM power source circuit | |
| Pre-heating control circuit | ||
| Compression | ||
| ECM | ||
| Fuel injection pump | ||
| Engine coolant temperature sensor | ||
| Fuel injection nozzle | ||
| Valve clearance | ||
| Fuel line (air bleed) | ||
| Hesitation/Poor acceleration (poor driveability) | Compression | |
| ECM | ||
| Fuel injection pump | ||
| Fuel injection nozzle | ||
| Fuel filter element assembly (level warning switch) | ||
| Brake override system | ||
| Knocking (poor driveability) | ECM | |
| Engine coolant temperature sensor | ||
| Fuel injection nozzle | ||
| Black smoke (poor driveability) | ECM | |
| Fuel injection pump | ||
| Fuel injection nozzle | ||
| Diesel throttle body | ||
| Intake air temperature sensor | ||
| White smoke (poor driveability) | Pre-heating control circuit | |
| ECM | ||
| Fuel injection pump | ||
| Engine coolant temperature sensor | ||
| Fuel injection nozzle | ||
| Fuel filter element assembly (level warning switch) | ||
| Diesel throttle body | ||
| Intake air temperature sensor | ||
| Surging/Hunting (poor driveability) | ECM | |
| Fuel injection pump | ||
| Fuel injection nozzle |