Tech Tips
Use the table below to help determine the cause of a problem. The likely causes of the problem are indicated in descending order. Check each suspected area in order. Repair or replace faulty parts or perform adjustments as necessary.
| Symptom | Suspected Area | Link |
|---|---|---|
| Engine does not crank (Does not start) | Battery | |
| Starter signal circuit | ||
| Entry and start system | ||
| VC output circuit (ECM 5 V output) | ||
| No initial combustion (Does not start) | Immobiliser system (w/ Entry and Start System) | |
| Immobiliser system (w/o Entry and Start System) | ||
| ECM power source circuit | ||
| VC output circuit (ECM 5 V output) | ||
| Crankshaft position sensor | ||
| Fuel pump control circuit | ||
| Ignition system | ||
| Fuel injector circuit | ||
| Valve timing | ||
| No. 1 valve rocker arm sub-assembly* | - | |
| Engine cranks normally but difficult to start | Fuel pump control circuit | |
| Fuel pump | ||
| Engine coolant temperature sensor | ||
| Ignition system | ||
| Fuel injector assembly | ||
| Compression | ||
| Fuel injector circuit | ||
| ECM power source circuit | ||
| Intake system | ||
| Throttle body assembly | ||
| Starter signal circuit | ||
| No. 1 valve rocker arm sub-assembly* | - | |
| Incomplete intermittent combustion occurs (Does not start) | Fuel pump control circuit | |
| Fuel pump | ||
| Fuel lines | - | |
| Ignition system | ||
| Fuel injector assembly | ||
| Crankshaft position sensor | ||
| Starter signal circuit | ||
| Valve timing | ||
| High engine speed (Poor idle) | Air conditioning signal circuit (for Automatic Air Conditioning System) | |
| Air conditioning signal circuit (for Manual Air Conditioning System) | ||
| Throttle body assembly | ||
| Intake system | ||
| Engine coolant temperature sensor | ||
| ECM power source circuit | ||
| PCV hose | - | |
| PCV valve | ||
| Low engine speed (Poor idle) | Fuel pump control circuit | |
| Throttle body assembly | ||
| Intake system | ||
| PCV hose | - | |
| PCV valve | ||
| Engine stalls on deceleration | Idle speed (refer to "Low engine speed" symptom) | - |
| Rough idle | Compression | |
| Air fuel ratio sensor | ||
| Heated oxygen sensor | ||
| Mass air flow meter sub-assembly | ||
| Ignition system | ||
| Fuel lines | - | |
| Fuel pump | ||
| Intake system | ||
| PCV hose | - | |
| PCV valve | ||
| No. 1 valve rocker arm sub-assembly* | - | |
| External part malfunction (Increase in load: A/C system, CVT system, etc.) | - | |
| Hunting (Poor idle) | PCV hose | - |
| PCV valve | ||
| Mass air flow meter sub-assembly | ||
| Air fuel ratio sensor | ||
| Engine stalls during air conditioning operation | Air conditioning signal circuit (for Automatic Air Conditioning System) | |
| Air conditioning signal circuit (for Manual Air Conditioning System) | Click here | |
| ECM | ||
| Hesitation/Poor acceleration (Poor driveability) | Fuel line | - |
| Fuel pump | ||
| Valve timing | ||
| Mass air flow meter sub-assembly | ||
| Throttle body assembly | ||
| Knock sensor | ||
| Fuel injector assembly | ||
| Ignition system | ||
| Compression | ||
| Brake override system | ||
| No. 1 valve rocker arm sub-assembly* | - | |
| Surging (Poor driveability) | Fuel line | - |
| Fuel pump control circuit | ||
| Fuel pump | ||
| Ignition system | ||
| Fuel injector assembly | ||
| No. 1 valve rocker arm sub-assembly* | - | |
| Engine stalls soon after starting | Mass air flow meter sub-assembly | |
| Intake system | ||
| Fuel line | - | |
| Valve timing | ||
| No. 1 valve rocker arm sub-assembly* | - |
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.