Crankshaft Position Sensor A Circuit Low
The P0337 code means the vehicle's onboard diagnostic system has detected: Crankshaft Position Sensor A Circuit Low. This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- moderate
- Estimated cost
- $80 - $350 (parts and labor)
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Common Symptoms
- Engine cranks but will not start
- Engine stalls suddenly
- Tachometer drops to zero
- Check Engine Light illuminated
- No spark or fuel injection
Probable Causes (Ranked by Likelihood)
- Short to ground in CKP sensor signal wiring Very High
- Faulty CKP sensor with internally shorted coil High
- Corroded or damaged CKP sensor connector High
- CKP sensor contaminated with oil or metal debris Moderate
- PCM input circuit failure Low
Step-by-Step Diagnostic Procedure
-
Check CKP sensor signal voltage during cranking -- should produce AC voltage; consistently low or zero indicates a fault
-
Test for shorts to ground in the signal wire with the sensor disconnected
-
Inspect the sensor tip for metal debris buildup from the reluctor ring -- clean or replace
-
Check the sensor connector for oil intrusion, corrosion, or damaged pins
-
Measure sensor coil resistance -- compare to manufacturer specification
Frequently Asked Questions
Can I drive with code P0337?
No. A low CKP circuit means the PCM is not receiving a proper engine position signal. The engine may not start or may stall unpredictably.
Can metal debris on the sensor cause P0337?
Yes. The CKP sensor uses a magnet, and metal shavings from the reluctor ring or engine components can accumulate on the sensor tip, disrupting the signal and causing a low reading.
How often should the CKP sensor be replaced?
CKP sensors do not have a standard replacement interval. They typically last the life of the engine. Replace only when faulty, not as preventive maintenance.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P0337 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
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