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 | |
| ST relay | ||
| Starter assembly | ||
| Flow chart [Starter signal circuit] | ||
| Flow chart [VC output circuit] | ||
| Entry and start system (for start function) | ||
| CAN communication system | ||
| Flow chart [ECM power source circuit] | ||
| Flow chart [Gateway ECU power source circuit] | ||
| No initial combustion (Does not start) | Immobiliser system | |
| Ignition circuit | ||
| Ignition system | ||
| Flow chart [ECM power source circuit] | ||
| Flow chart [VC output circuit] | ||
| Flow chart [Fuel pump control circuit] | ||
| Fuel pump | ||
| Fuel injector circuit | ||
| Fuel injector assembly | ||
| Crankshaft position sensor | ||
| Camshaft position sensor (for intake camshaft) | ||
| Camshaft position sensor (for exhaust camshaft) | ||
| ECM | ||
| Valve timing (check for loose or jumped teeth on timing chain) | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine cranks normally but difficult to start | Flow chart [Fuel pump control circuit] | |
| Fuel pump | ||
| Fuel injector circuit | ||
| Fuel injector assembly | ||
| Ignition circuit | ||
| Ignition system | ||
| Spark plug | ||
| Intake system | ||
| Throttle body with motor assembly | ||
| Engine coolant temperature sensor | ||
| PCV valve | ||
| PCV hose | ||
| Crankshaft position sensor | ||
| Flow chart [ECM power source circuit] | ||
| Flow chart [Starter signal circuit] | ||
| Compression | ||
| Valve timing (check for loose or jumped teeth on timing chain) | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Incomplete intermittent combustion occurs (Does not start) | Flow chart [Fuel pump control circuit] | |
| Fuel pump | ||
| Fuel lines | - | |
| Ignition circuit | ||
| Ignition system | ||
| Spark plug | ||
| Fuel injector circuit | ||
| Fuel injector assembly | ||
| Engine coolant temperature sensor | ||
| Crankshaft position sensor | ||
| Camshaft position sensor (for intake camshaft) | ||
| Camshaft position sensor (for exhaust camshaft) | ||
| Throttle body with motor assembly | ||
| Intake system | ||
| Compression | ||
| Valve timing (check for loose or jumped teeth on timing chain) | ||
| High engine speed | Intake system | |
| Throttle body with motor assembly | ||
| PCV valve | ||
| PCV hose | ||
| Engine coolant temperature sensor | ||
| Flow chart [ECM power source circuit] | ||
| Air conditioning signal circuit | ||
| Low engine speed (Poor idle) | Flow chart [Fuel pump control circuit] | |
| Fuel injector assembly | ||
| Fuel pump | ||
| Fuel lines | - | |
| Throttle body with motor assembly | ||
| Intake system | ||
| PCV valve | ||
| PCV hose | ||
| Air conditioning signal circuit | ||
| Rough idle | Throttle body with motor assembly | |
| Engine coolant temperature sensor | ||
| Heated oxygen sensor (sensor 1) | ||
| Heated oxygen sensor (sensor 2) | ||
| Mass air flow meter | ||
| Manifold absolute pressure sensor | ||
| Ignition circuit | ||
| Ignition system | ||
| Knock sensor | ||
| Intake system | ||
| Purge VSV | ||
| PCV valve | ||
| PCV hose | ||
| Fuel injector circuit | ||
| Fuel injector assembly | ||
| Flow chart [Fuel pump control circuit] | ||
| Fuel pump | ||
| Fuel line | - | |
| Compression | ||
| Valve timing (check for loose or jumped teeth on timing chain) | ||
| No. 1 valve rocker arm sub-assembly* | ||
| External part malfunction (Increase in load: A/C system, etc.) | - | |
| Hunting (Poor idle) | Throttle body with motor assembly | |
| Intake system | ||
| Mass air flow meter | ||
| PCV valve | ||
| PCV hose | ||
| Flow chart [Fuel pump control circuit] | ||
| Fuel pump | ||
| Hesitation and/or poor acceleration (Poor driveability) | Flow chart [Fuel pump control circuit] | |
| Fuel pump | ||
| Fuel lines | - | |
| Throttle body with motor assembly | ||
| Fuel injector circuit | ||
| Fuel injector assembly | ||
| Mass air flow meter | ||
| Intake system | ||
| Ignition system | ||
| Ignition circuit | ||
| Knock sensor | ||
| Flow chart [Brake override system] | ||
| Variable Valve Timing (VVT) system | ||
| Compression | ||
| Valve timing (check for loose or jumped teeth on timing chain) | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Lack of power | Flow chart [Cooling System] | |
| Supercharger assembly | ||
| Surging (Poor driveability) | Flow chart [Fuel pump control circuit] | |
| Fuel pump | ||
| Fuel lines | - | |
| Mass air flow meter | ||
| Fuel injector circuit | ||
| Fuel injector assembly | ||
| Ignition circuit | ||
| Ignition system | ||
| Spark plug | ||
| Flow chart [ECM power source circuit] | ||
| Variable Valve Timing (VVT) system | ||
| Compression | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine stalls soon after starting | Flow chart [Fuel pump control circuit] | |
| Fuel pump | ||
| Fuel lines | - | |
| Throttle body with motor assembly | ||
| Mass air flow meter | ||
| Intake system | ||
| Ignition circuit | ||
| Ignition system | ||
| Spark plug | ||
| Fuel injector circuit | ||
| Fuel injector assembly | ||
| Manifold absolute pressure sensor | ||
| Crankshaft position sensor | ||
| Flow chart [ECM power source circuit] | ||
| Compression | ||
| Valve timing (check for loose or jumped teeth on timing chain) | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine stalls only during A/C operation | Air conditioning signal circuit | |
| ECM | ||
| MIL (Malfunction Indicator Lamp) malfunction | Flow chart [MIL Circuit] | |
| Meter/Gauge system |
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 (the engine speed at which fuel cut occurs + 500 rpm or more). In this situation, there is a possibility that a No. 1 valve rocker arm sub-assembly will become loose and malfunction, check that the No. 1 valve rocker arm sub-assemblies are properly installed.
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