P1242 – Fuel Level Sensor High Input
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Symptoms
- Gauge stuck on full
- Incorrect range estimate
- Low fuel warning inoperative
- Check engine light
- Emissions readiness issues
Causes
- Short to power
- Faulty sensor
- Connector corrosion
- ECU input fault
- Incorrect wiring repair
Diagnosis
- Measure sensor voltage
- Check wiring for shorts
- Inspect connector
- Compare to actual fuel level
- Scan live data
Repair
- Repair wiring
- Replace fuel level sensor
- Clean connectors
- Correct wiring repairs
- Update ECU if needed