P0372
Timing Reference High Resolution Signal A Too Few Pulses
Ignition / engine timing
Generic OBD-II
High
What it means
P0372 means the ECM counted fewer pulses than expected on the high-resolution timing reference signal A — the precise crank/cam signal it uses to time spark and fuel. Missing pulses point to a failing timing sensor, its wiring, or a damaged reluctor wheel, and can cause misfires, poor running, or a no-start, so it should be diagnosed promptly.
High
Can I keep driving? It may run poorly, misfire, or fail to start — treat this as urgent and be prepared for a possible no-start.
Common symptoms
What you'll notice
- Check-engine light on
- Misfire, rough running, or hesitation
- Hard starting or intermittent no-start
- Reduced power or stalling
Common causes
Most likely first
- Faulty high-resolution timing reference sensor (optical/Hall sensor)Likely
- Open, shorted, or chafed wiring in the timing reference signal circuitCommon
- Poor or corroded connection at the sensorCommon
- Damaged crank/cam reluctor ring or tone wheel with missing teethLess often
- Faulty ECM (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the fault is the high-resolution timing reference signal A.
- Inspect the sensor's connector and wiring for damage, corrosion, or an open.
- Check the signal, power, and ground at the sensor against specification.
- Inspect the reluctor/tone wheel for damaged or missing teeth and debris.
- If the circuit and wheel are good, replace the high-resolution timing reference sensor. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0372?+
No — the ECM relies on this timing signal to fire the engine correctly. A dropout can cause stalling or a no-start, so address it before driving further.
Can I just clear P0372?+
It will return until the sensor, wiring, or reluctor wheel is repaired, and clearing won't stop a stall if the signal keeps dropping.
Related codes
Often seen with P0372
Read & clear P0372 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