OBD-II FAULT CODE
P0378
Timing Reference High Resolution Signal B Intermittent/Erratic Pulses
Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P0378.
- Check Engine light
- Poor drivability or reduced fuel economy depending on fault
- No-start, rough running, limp mode or poor power possible
- Faulty cam/crank sensor
- Oil level/quality issue
- VVT solenoid fault
- Timing chain/belt issue
- Wiring fault
- Scan all modules and record freeze-frame data before clearing codes
- Check battery voltage and related fuses
- Check oil level/condition
- Inspect sensor/solenoid connectors
- Compare cam/crank correlation with scan data
- Repair wiring or replace confirmed failed sensor/solenoid
- Investigate mechanical timing if correlation faults remain
- Repair ground/signal circuit or replace confirmed faulty sensor
- Clean/secure connector and repair damaged harness
Related Codes
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Disclaimer: Information is provided for general guidance only and may not apply to all vehicles. Always consult a qualified technician.