P0338
Crankshaft Position Sensor A Circuit High
Ignition / engine position
Generic OBD-II
High
What it means
P0338 means the crankshaft position sensor "A" signal is reading abnormally high. The ECM relies on this sensor to track crankshaft speed and position for spark and fuel timing, so a bad signal can cause hard starting, stalling, or a no-start, making this a fault worth addressing quickly.
High
Can I keep driving? Risky — the crankshaft sensor is essential for spark and fuel timing, so the engine may stall, run rough, or fail to restart. Fix it before relying on the car.
Common symptoms
What you'll notice
- Check-engine light on
- Hard starting, or no-start in some cases
- Stalling or intermittent cut-outs while driving
- Rough running, hesitation, or reduced power
Common causes
Most likely first
- Failed crankshaft position sensorLikely
- Damaged wiring or a short to voltage in the sensor circuitCommon
- Corroded or loose connector at the sensorCommon
- Air-gap or reluctor-ring/tone-wheel damageLess often
- ECM fault (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and note whether the fault is constant or intermittent.
- Inspect the sensor connector and wiring for damage, chafing, or corrosion.
- Check the circuit for a short to voltage and confirm correct reference/ground.
- Verify the sensor air gap and inspect the reluctor ring for damaged teeth.
- Replace the crankshaft position sensor if it tests faulty; clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0338?+
Not recommended. A failing crankshaft sensor can cause a sudden stall, so have it repaired before depending on the vehicle.
Can I just clear P0338?+
It will return as soon as the ECM sees the faulty signal again. The sensor or wiring must be repaired first.
Related codes
Often seen with P0338
Read & clear P0338 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