When the malfunction is not confirmed in the DTC (Diagnostic Trouble Code) check and the problem still cannot be confirmed in the basic inspection, use this table and troubleshoot according to the priority order given below.
| Symptom | Suspected Area | See page |
|---|---|---|
| Engine does not crank (Does not start) | 1. Starter | |
| 2. Starter relay | ||
| 3. Starter signal circuit | ||
| No initial combustion (Does not start) | 1. ECM power source circuit | |
| 2. Pre-heating control circuit | ||
| 3. Compression | ||
| 4. ECM | ||
| 5. Fuel injection pump | ||
| Cold engine (Difficult to start) | 1. Pre-heating control circuit | |
| 2. Starter signal circuit | ||
| 3. Engine coolant temperature sensor | ||
| 4. Fuel injection nozzle | ||
| 5. Fuel filter | ||
| 6. Venturi | ||
| 7. ECM | ||
| 8. Fuel injection pump | ||
| Hot engine (Difficult to start) | 1. Starter signal circuit | |
| 2. Fuel injection nozzle | ||
| 3. Fuel filter | ||
| 4. Venturi | ||
| 5. ECM | ||
| 6. Fuel injection pump | ||
| Engine stall (Soon after starting) | 1. Fuel filter | |
| 2. Venturi | ||
| 3. ECM | ||
| 4. Fuel injection pump | ||
| Engine stall (Other) | 1. ECM power source circuit | |
| 2. Venturi | ||
| 3. ECM | ||
| 4. Fuel injection pump | ||
| Incorrect first idle (Poor idling) | 1. Engine coolant temperature sensor | |
| 2. Fuel filter | ||
| 3. ECM | ||
| 4. Fuel injection pump | ||
| High engine idle speed (Poor idling) | 1. Air conditioning signal circuit | |
| 2. Engine coolant temperature sensor | ||
| 3. ECM | ||
| 4. Fuel injection pump | ||
| Low engine idle speed (Poor idling) | 1. Air conditioning signal circuit | |
| 2. Fuel injection nozzle | ||
| 3. Engine coolant temperature sensor | ||
| 4. Venturi | ||
| 5. Compression | ||
| 6. Valve clearance | ||
| 7. Fuel line (Air bleed) | ||
| 8. ECM | ||
| 9. Fuel injection pump | ||
| Rough idling (Poor idling) | 1. Fuel injection nozzle | |
| 2. Fuel line (Air bleed) | ||
| 3. Pre-heating control circuit | ||
| 4. Venturi | ||
| 5. Compression | ||
| 6. Valve clearance | ||
| 7. ECM | ||
| 8. Fuel injection pump | ||
| Hunting when engine is hot (Poor idling) | 1. Fuel injection nozzle | |
| 2. ECM power source circuit | ||
| 3. Compression | ||
| 4. Fuel line (Air bleed) | ||
| 5. Valve clearance | ||
| 6. ECM | ||
| 7. Fuel injection pump | ||
| Hunting when engine is cold (Poor idling) | 1. Pre-heating control circuit | |
| 2. Fuel injection nozzle | ||
| 3. ECM power source circuit | ||
| 4. Engine coolant temperature sensor | ||
| 5. Compression | ||
| 6. Fuel line (Air bleed) | ||
| 7. Valve clearance | ||
| 8. ECM | ||
| 9. Fuel injection pump | ||
| Hesitation/Poor acceleration (Poor driveability) | 1. Fuel injection nozzle | |
| 2. Fuel filter | ||
| 3. Compression | ||
| 4. ECM | ||
| 5. Fuel injection pump | ||
| 6. Brake override system | ||
| Knocking (Poor driveability) | 1. Fuel injection nozzle | |
| 2. Engine coolant temperature sensor | ||
| 3. ECM | ||
| Black smoke (Poor driveability) | 1. Fuel injection nozzle | |
| 2. Venturi | ||
| 3. Intake air temperature sensor | ||
| 4. ECM | ||
| 5. Fuel injection pump | ||
| White smoke (Poor driveability) | 1. Pre-heating control circuit | |
| 2. Fuel injection nozzle | ||
| 3. Fuel filter | ||
| 4. Venturi | ||
| 5. Engine coolant temperature sensor | ||
| 6. Intake air temperature sensor | ||
| 7. ECM | ||
| 8. Fuel injection pump | ||
| Surging/Hunting (Poor driveability) | 1. Fuel injection nozzle | |
| 2. ECM | ||
| 3. Fuel injection pump |