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.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.
| Symptom | Suspected Area | Link |
|---|---|---|
| Engine does not crank (Does not start) | Battery | |
| VC output circuit (ECM 5 V output) | ||
| Entry and start system (for Start Function) | ||
| Starter signal circuit | ||
| Engine immobiliser system | ||
| Starter assembly | ||
| No initial combustion (Does not start) | Engine immobiliser system | |
| ECM power source circuit | ||
| VC output circuit (ECM 5 V output) | ||
| Crankshaft position sensor | ||
| VVT sensor (for intake side) | ||
| VVT sensor (for exhaust side) | ||
| Ignition system | ||
| Fuel injector circuit | ||
| Valve timing | ||
| Starter signal circuit | ||
| Fuel pump control circuit | ||
| ECM | ||
| Engine cranks normally but difficult to start | Engine coolant temperature sensor | |
| Ignition system | ||
| Fuel injector assembly | ||
| Compression | ||
| Fuel injector circuit | ||
| Intake system | ||
| Throttle body with motor assembly | ||
| ECM power source circuit | ||
| Starter signal circuit | ||
| Fuel pump control circuit | ||
| Incomplete intermittent combustion occurs (Does not start) | Fuel line | - |
| Ignition system | ||
| Fuel injector assembly | ||
| Crankshaft position sensor | ||
| Valve timing | ||
| Fuel pump control circuit | ||
| High engine speed | Air conditioning signal circuit | |
| Throttle with motor body assembly | ||
| Engine coolant temperature sensor | ||
| PCV valve and hose | ||
| ECM power source circuit | ||
| Low engine speed (Poor idle) | Throttle body with motor assembly | |
| Intake system | ||
| PCV valve and hose | ||
| Fuel pump control circuit | ||
| Rough idle | Compression (engine mechanical) | |
| Air fuel ratio sensor | ||
| Heated oxygen sensor | ||
| Mass air flow meter sub-assembly | ||
| Ignition system | ||
| Air conditioning signal circuit | ||
| Fuel line | - | |
| Valve timing | ||
| Intake system | ||
| PCV valve and hose | ||
| Fuel pump control circuit | ||
| External part malfunction (Increase in load: A/C system, A/T system, etc.) | - | |
| Hunting (Poor idle) | PCV valve and hose | |
| Mass air flow meter sub-assembly | ||
| Air fuel ratio sensor | ||
| Engine stalls during air conditioning operation | Air conditioning signal circuit | |
| ECM | ||
| Hesitation/Poor acceleration (Poor driveability) | Fuel line | - |
| Valve timing | ||
| Mass air flow meter sub-assembly | ||
| Throttle body with motor assembly | ||
| Knock control sensor | ||
| Fuel pump control circuit | ||
| Brake override system | ||
| Surging (Poor driveability) | Fuel line | - |
| Ignition system | ||
| Fuel injector assembly | ||
| Fuel pump control circuit | ||
| Engine stalls soon after starting | Mass air flow meter sub-assembly | |
| Intake system | ||
| Fuel line | - |