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 | |
| Starter assembly | ||
| Smart entry and start system (for start function) | ||
| Park/Neutral position switch assembly | ||
| VC output circuit (ECM 5 V circuit) | ||
| Starter signal circuit | ||
| ECM power source circuit | ||
| No initial combustion (Does not start) | Engine immobiliser system | |
| VC output circuit (ECM 5 V circuit) | ||
| ECM power source circuit | ||
| Crankshaft position sensor | ||
| Camshaft position sensor (for intake camshaft) | ||
| Camshaft position sensor (for exhaust camshaft) | ||
| Valve timing | ||
| Ignition system | ||
| Fuel pump control circuit | ||
| Fuel injector circuit | ||
| Starter signal circuit | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine cranks normally but difficult to start | Fuel pump control circuit | |
| Engine coolant temperature sensor | ||
| Ignition system | ||
| Compression | ||
| Fuel injector assembly | ||
| Fuel injector circuit | ||
| Intake system | ||
| Throttle body with motor assembly | ||
| PCV valve and hose | ||
| Starter signal circuit | ||
| ECM power source circuit | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Incomplete intermittent combustion occurs (Does not start) | Fuel pump control circuit | |
| Fuel pump | ||
| Fuel line | - | |
| Ignition system | ||
| Fuel injector circuit | ||
| ECM power source circuit | ||
| Starter signal circuit | ||
| Crankshaft position sensor | ||
| Camshaft position sensor (for intake camshaft) | ||
| Camshaft position sensor (for exhaust camshaft) | ||
| Valve timing | ||
| High engine speed | Throttle body with motor assembly | |
| Intake system | ||
| A/C signal circuit | ||
| ECM power source circuit | ||
| Engine coolant temperature sensor | ||
| PCV valve and hose | ||
| Low engine speed (Poor idle) | Throttle body with motor assembly | |
| A/C signal circuit | ||
| Fuel pump control circuit | ||
| Fuel pump | ||
| Intake system | ||
| PCV valve and hose | ||
| Rough idle | Compression | |
| Ignition system | ||
| Spark plug | ||
| Fuel injector circuit | ||
| ECM power source circuit | ||
| Fuel pump control circuit | ||
| Fuel pump | ||
| Fuel line | - | |
| Throttle body with motor assembly | ||
| Intake system | ||
| Purge VSV | ||
| PCV valve and hose | ||
| Air fuel ratio sensor | ||
| Heated oxygen sensor | ||
| Mass air flow meter sub-assembly | ||
| Knock control sensor | ||
| External part malfunction (Increase in load: A/C system, etc.) | - | |
| Intake air control valve actuator for tumble control valve (w/ tumble control valve) | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Hunting (Poor idle) | Electronic throttle control system | |
| Intake system | ||
| ECM power source circuit | ||
| Intake air control valve actuator for tumble control valve (w/ tumble control valve) | ||
| Drive start control system | ||
| Hesitation and/or poor acceleration (Poor driveability) | Fuel pump control circuit | |
| Spark plug | ||
| Ignition system | ||
| Fuel injector assembly | ||
| Mass air flow meter sub-assembly | ||
| Electronic throttle control system | ||
| Intake system | ||
| Compression | ||
| Brake override system | ||
| Drive start control system | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Surging (Poor driveability) | Spark plug | |
| Fuel pump control circuit | ||
| Ignition system | ||
| Fuel injector assembly | ||
| Mass air flow meter sub-assembly | ||
| Variable Valve Timing (VVT) system | ||
| Compression | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine stalls soon after starting | Engine immobiliser system | |
| Fuel pump control circuit | ||
| Spark plug | ||
| Ignition system | ||
| Fuel injector assembly | ||
| Variable Valve Timing (VVT) system | ||
| Electronic throttle control system | ||
| Intake system | ||
| PCV valve and hose | ||
| Compression | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine stalls only during A/C operation | A/C signal circuit | |
| ECM | ||
| Drive mode does not change | Drive mode switch 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.