SFI SYSTEM PROBLEM SYMPTOMS TABLE
Tech Tips
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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.
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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 | ||
| VC output circuit (ECM 5 V output) | ||
| Starter signal circuit | ||
| No initial combustion (Does not start) | Engine immobiliser system (w/ smart entry and start system) | |
| Engine immobiliser system (w/o smart entry and start system) | ||
| ECM power source circuit | ||
| Crankshaft position sensor | ||
| Ignition system | ||
| Fuel pump control circuit | ||
| Fuel injector circuit | ||
| Valve timing | ||
| VC output circuit (ECM 5 V output) | ||
| Camshaft position sensor | ||
| Starter signal circuit | ||
| ECM | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine cranks normally but difficult to start | Fuel pump control circuit | |
| Fuel pump | ||
| Fuel injector circuit | ||
| Engine coolant temperature sensor | ||
| Intake system | ||
| Ignition system | ||
| Spark plug | ||
| Throttle body with motor assembly | ||
| Compression | ||
| 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 | ||
| Ignition circuit | ||
| Ignition system | ||
| Fuel injector circuit | ||
| ECM power source circuit | ||
| Crankshaft position sensor | ||
| Valve timing | ||
| Camshaft position sensor | ||
| 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 | ||
| Throttle body with motor assembly | ||
| Intake system | ||
| PCV valve and hose | ||
| Air fuel ratio sensor | ||
| Heated oxygen sensor | ||
| Mass air flow meter sub-assembly | ||
| 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 | ||
| PCV valve and hose | ||
| Air fuel ratio sensor | ||
| Mass air flow meter sub-assembly | ||
| Hesitation/poor acceleration | Fuel pump control circuit | |
| Fuel pump | ||
| Spark plug | ||
| Ignition system | ||
| Fuel injector circuit | ||
| ECM power source circuit | ||
| Mass air flow meter sub-assembly | ||
| Throttle body with motor assembly | ||
| Intake 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 system | ||
| Fuel injector circuit | ||
| ECM power source 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 | Fuel pump control circuit | |
| Fuel pump | ||
| Spark plug | ||
| Ignition system | ||
| Fuel injector circuit | ||
| ECM power source circuit | ||
| Mass air flow meter sub-assembly | ||
| Variable valve timing (VVT) system | ||
| Throttle body with motor assembly | ||
| 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 |
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 valve rocker arm will become loose and malfunction, so check that the No. 1 valve rocker arm sub-assembly is properly attached Click here.