P0370
Timing Reference High Resolution Signal A
Ignition timing reference
Generic OBD-II
High
What it means
P0370 means the engine computer has detected a problem with the "A" high-resolution timing-reference signal it uses to precisely track engine position. Because this signal sets ignition and fuel timing, a fault can cause hard starting, stalling, or a no-start — most often from the sensor, its wiring, or a damaged reluctor ring.
High
Can I keep driving? Risky — a lost timing-reference signal can cause stalling or a no-start; repair it promptly.
Common symptoms
What you'll notice
- Check-engine light on
- Hard starting, stalling, or no-start
- Rough idle and hesitation
- Reduced power or intermittent cutting out
Common causes
Most likely first
- Faulty high-resolution timing/reference sensor (crank or cam signal source)Likely
- Corroded, loose, or damaged connector at the sensorCommon
- Open, shorted, or intermittent wiring in the signal circuitCommon
- Damaged reluctor/tone ring producing an erratic signalLess often
- ECM fault (rare)Less often
How to diagnose & fix
Work through it in order
- Inspect the timing-reference sensor connector and wiring for corrosion, chafing, or looseness.
- Check the signal on a scan tool or scope for dropouts, especially while cranking.
- Inspect the reluctor/tone ring for damage or debris.
- Replace the sensor if it is out of spec, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0370?+
Not really — this signal sets ignition and injection timing, so the engine may stall or fail to start without warning.
Can I just clear P0370?+
It returns once the signal fault reappears, and clearing it won't prevent a stall. Fix the wiring or sensor first.
Related codes
Often seen with P0370
Read & clear P0370 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