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 | See page |
|---|---|---|
| Engine does not crank (Does not start) | Battery | |
| VC output circuit (ECM 5 V output) | ||
| Starter signal circuit | ||
| Smart entry and start system | ||
| Starter assembly | ||
| No initial combustion (Does not start) | Immobiliser system | |
| ECM power source circuit | ||
| VC output circuit (ECM 5 V output) | ||
| Crankshaft position sensor | ||
| VVT sensor (for intake camshaft) | ||
| VVT sensor (for exhaust camshaft) | ||
| Ignition system | ||
| Fuel injector circuit | ||
| Valve timing | ||
| Starter signal circuit | ||
| Fuel pump control circuit | ||
| ECM | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine cranks normally but difficult to start | Flow chart [Engine difficult to start] | |
| Engine coolant temperature sensor | ||
| Ignition system | ||
| Fuel injector assembly | ||
| Compression | ||
| Fuel injector circuit | ||
| Intake system | ||
| Throttle with motor body assembly | ||
| ECM power source circuit | ||
| Starter signal circuit | ||
| Fuel pump control circuit | ||
| No. 1 valve rocker arm sub-assembly* | ||
| 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 with motor body assembly | |
| Intake system | ||
| PCV valve and hose | ||
| Fuel pump control circuit | ||
| Engine stalls on deceleration | Flow chart [Engine stalls] | |
| Idle speed (refer to "Low engine speed") | ||
| Rough idle | Flow chart [Rough idling] | |
| 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.) | - | |
| No. 1 valve rocker arm sub-assembly* | ||
| Hunting (Poor idle) | PCV valve and hose | |
| Mass air flow meter sub-assembly | ||
| Air fuel ratio sensor | ||
| Lack of power | Flow chart [Lack of power] | |
| 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 with motor body assembly | ||
| Knock control sensor | ||
| Fuel pump control circuit | ||
| Brake override system | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Surging (Poor driveability) | Fuel line | - |
| Ignition system | ||
| Fuel injector assembly | ||
| Fuel pump control circuit | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine stalls soon after starting | Flow chart [Engine stalls] | |
| Mass air flow meter sub-assembly | ||
| Intake system | ||
| Fuel line | - | |
| No. 1 valve rocker arm sub-assembly* | ||
| Engine vibrates frequently when idling (Active control engine mount system) | Active control engine mount circuit |
Tech Tips
*: Check the "Fuel Cut Elps Time" in the Data List.
If the elapsed time is over 0 sec, then the engine speed is high (More than the engine speed at which fuel cut occurs + 500 rpm).
When this has happened, there is the possibility that the No. 1 valve rocker arm sub-assembly will become loose and malfunction, so check that the No. 1 valve rocker arm sub-assembly is properly attached Click here.