Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Problem Symptoms Table
HINT:
Use the table below to help determine the cause of the problem. The potential cases 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.
SFI SYSTEM
| Symptom | Suspected area |
|---|---|
| Engine does not crank (Does not start) | 1. Check push-start function initialization |
| 2. Immobilizer System | |
| 3. ECM power source circuit | |
| 4. VC output circuit | |
| 5. Cranking holding function circuit | |
| 6. Starter | |
| No initial combustion (Does not start) | 1. ECM power source circuit |
| 2. Fuel pump control circuit | |
| 3. ECM | |
| Engine cranks normally but difficult to start | 1. Fuel pump control circuit |
| 2. Fuel pump for high pressure | |
| 3. Compression | |
| Difficult to start with cold engine | 1. Cranking holding function circuit |
| 2. Ignition system | |
| 3. Spark plug | |
| 4. Fuel pump control circuit | |
| 5. Fuel pump for high pressure | |
| 6. Fuel injector for direct injection | |
| 7. Fuel injector for port injection | |
| Difficult to start with worm engine | 1. Cranking holding function circuit |
| 2. Fuel injector for port injection | |
| 3. Fuel injector for direct injection | |
| 4. Ignition system | |
| 5. Spark plug | |
| 6. Fuel pump control circuit | |
| 7. Fuel pump for high pressure | |
| High engine idle speed (Poor idling) | 1. ECM power source circuit |
| 2. A/C signal circuit (compressor circuit) | |
| 3. Electronic throttle control system | |
| 4. Air induction system | |
| 5. PCV hose | |
| Low engine idle speed (Poor idling) | 1. A/C signal circuit (compressor circuit) |
| 2. Fuel pump control circuit | |
| 3. Fuel pump for high pressure | |
| 4. Electronic throttle control system | |
| 5. Air induction system | |
| 6. PCV hose | |
| Rough idling (Poor idling) | 1. Compression |
| 2. Fuel pump control circuit | |
| 3. Fuel pump for high pressure | |
| 4. Electronic throttle control system | |
| 5. Air induction system | |
| 6. PCV hose | |
| Hunting (Poor idling) | 1. ECM power source circuit |
| 2. Fuel pump control circuit | |
| 3. Fuel pump for high pressure | |
| 4. Spark plug | |
| 5. Ignition system | |
| 6. Fuel injector for port injection | |
| 7. Fuel injector for direct injection | |
| 8. Electronic throttle control system | |
| 9. Air induction system | |
| 10. PCV hose | |
| Hesitation/ Poor acceleration (Poor driveability) | 1. Fuel pump control circuit |
| 2. Fuel pump for high pressure | |
| 3. Spark plug | |
| 4. Ignition system | |
| 5. Fuel injector for port injection | |
| 6. Fuel injector for direct injection | |
| Surging (Poor driveability) | 1. Spark plug |
| 2. Fuel pump control circuit | |
| 3. Fuel pump for high pressure | |
| 4. Ignition system | |
| 5. Fuel injector for port injection | |
| 6. Fuel injector for direct injection | |
| Engine stalls soon after starting | 1. Fuel pump control circuit |
| 2. Fuel pump for high pressure | |
| 3. Spark plug | |
| 4. Ignition system | |
| 5. Fuel injector for port injection | |
| 6. Fuel injector for direct injection | |
| Engine stalls during A/C operation | 1. A/C signal circuit (Compressor circuit) |
| 2. ECM | |
| Unable/difficult refuel | 1. Refueling valve (canister) |
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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