What Does P0337 Mean?
The crankshaft position sensor A circuit is reporting a low input signal to the ECM. The voltage from the CKP sensor is below the expected minimum threshold, indicating the sensor is producing too weak of a signal or the circuit has a fault pulling the signal low. The engine may misfire, run rough, stall, or fail to start depending on how degraded the signal is.
Safety Warning
Do not drive if the engine is stalling or misfiring severely. A low CKP signal can cause the ECM to lose sync with the crankshaft, resulting in sudden stalling at any speed. If the engine is running relatively normally, limit driving to short, low-speed trips to a repair facility.
Common Causes
35%
Failing CKP sensor with weakened magnetic element producing insufficient signal voltage
25%
Excessive air gap between CKP sensor and reluctor ring reducing signal amplitude below detection threshold
20%
Short to ground in the CKP sensor signal wire pulling the voltage low
10%
Metallic debris or oil contamination on the CKP sensor tip dampening the magnetic signal
10%
Poor ground connection for the CKP sensor circuit
Diagnostic Steps
1
Check the CKP sensor signal voltage on live data or with a multimeter (AC voltage on magnetic sensors) while cranking — most magnetic CKP sensors should produce at least 200mV AC during cranking; significantly lower indicates a weak sensor or excessive gap.
2
Remove the CKP sensor and inspect the tip for metallic debris accumulation or oil contamination — clean the sensor face and the reluctor ring area thoroughly.
3
Measure the CKP sensor air gap with a feeler gauge — if the gap exceeds specification (typically >1.5mm), the signal amplitude drops below the ECM detection threshold.
4
Disconnect the CKP sensor and check the signal wire for short to ground by measuring resistance between the signal pin and chassis ground — should read infinite (OL); any low reading indicates a wiring short.
5
Verify the CKP sensor ground circuit has less than 0.1 ohm resistance back to the ECM ground pin — a high-resistance ground reduces the effective signal voltage.
Estimated Repair Cost
$80 - $450
Parts + labor, varies by vehicle and location
The crankshaft position sensor A circuit is reporting a low input signal to the ECM. The voltage from the CKP sensor is below the expected minimum threshold, indicating the sensor is producing too weak of a signal or the circuit has a fault pulling the signal low. The engine may misfire, run rough, ...
The most common cause of P0337 (Crankshaft Position Sensor A Circuit Range/Performance) is: Failing CKP sensor with weakened magnetic element producing insufficient signal voltage
Typical repair costs for P0337 range from $80 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Do not drive if the engine is stalling or misfiring severely. A low CKP signal can cause the ECM to lose sync with the crankshaft, resulting in sudden stalling at any speed. If the engine is running relatively normally, limit driving to short, low-speed trips to a repair facility.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0337 to identify the root cause.
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Quick Info
Category
Powertrain
System
Ignition System
Difficulty
Type
Generic (SAE)
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