P0371
Timing Reference High Resolution Signal A Too Many Pulses
Ignition / engine position
Generic OBD-II
High
What it means
P0371 means the ECM is counting more pulses than expected on the "A" high-resolution timing reference signal. This signal, generated by the crank/cam sensing system, tells the computer exactly where the engine is in its cycle. Too many pulses throws off timing, which can cause misfires, rough running, and hard starting until the sensor or reluctor is repaired.
High
Can I keep driving? Can be unpredictable — the ECM relies on this timing signal, so the engine may misfire, stall, or become hard to start. Have it diagnosed before depending on the car.
Common symptoms
What you'll notice
- Check-engine light on
- Engine misfires or runs rough
- Hesitation, stumbling, or reduced power
- Hard starting or intermittent stalling
Common causes
Most likely first
- Faulty high-resolution timing reference sensorLikely
- Damaged crankshaft or camshaft sensor or its wiringCommon
- Damaged crank/cam reluctor ring or tone wheelCommon
- Electrical interference or a poor ground on the signal circuitLess often
- ECM fault (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for related crank/cam sensor codes.
- Inspect the reference sensor connector and wiring for damage or corrosion.
- Check the signal circuit for a solid ground and freedom from interference.
- Inspect the reluctor ring/tone wheel for chipped or damaged teeth.
- Replace the high-resolution reference sensor if it tests faulty; clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0371?+
Not ideal. A faulty timing reference can cause sudden misfires or stalling, so it's best diagnosed before you rely on the vehicle.
Can I just clear P0371?+
It returns as soon as the ECM sees the extra pulses again. The sensor or reluctor problem must be repaired first.
Related codes
Often seen with P0371
Read & clear P0371 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX