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