OBD-II code P0337 indicates that the powertrain control module (PCM) has detected a lower-than-expected voltage signal from the crankshaft position (CKP) sensor circuit. This typically means the sensor or its wiring is faulty, preventing the engine from accurately tracking crankshaft position and timing.
The sensor itself may have failed due to internal wear, contamination, or damage, resulting in a weak or absent signal.
Wiring harness issues, such as frayed wires, corrosion, or loose connections, can cause a low-voltage signal or intermittent circuit failure.
If the sensor is not properly aligned with the reluctor ring or the gap is too large, it may produce a weak or inconsistent signal.
A damaged, cracked, or contaminated reluctor ring (crankshaft trigger wheel) can disrupt the sensor’s ability to generate a proper signal.
A short in the wiring harness or sensor circuit can pull the voltage low, triggering the code.
While uncommon, a malfunctioning PCM could incorrectly interpret the sensor signal. This is a last-resort diagnosis after all other causes are ruled out.
Driving with this code is risky, as the engine may stall unexpectedly or fail to start. Immediate diagnosis and repair are recommended.
No, the PCM is rarely the cause of P0337. The issue is almost always related to the sensor, wiring, or reluctor ring. PCM replacement should only be considered after all other possibilities are exhausted.
If the sensor tests within specifications but the code persists, the issue may lie in the wiring, connector, or reluctor ring. A thorough inspection of the entire circuit is necessary.
While a weak battery or faulty alternator can cause electrical issues, they are unlikely to directly trigger P0337. However, low system voltage can sometimes contribute to sensor signal problems.