Crankshaft Position Sensor A Range/Performance
Diagnostic trouble code P0336 indicates that the Powertrain Control Module (PCM) has detected an irregular, missing, or out-of-range signal from the Crankshaft Position Sensor 'A' circuit. The PCM relies on this signal to determine engine RPM and crankshaft position for proper fuel injection and ignition timing, and sets this code when the signal does not match expected parameters.
This code is considered high severity because a faulty crankshaft position signal can cause the engine to stall unexpectedly while driving or prevent the vehicle from starting, posing a significant safety risk.
Common symptoms
- Illuminated Check Engine Light
- Engine cranks but will not start
- Engine stalling or hesitation while driving
- Rough idling or misfiring
- Decreased engine performance and fuel economy
Likely causes
- Faulty crankshaft position sensor
- Damaged, corroded, or loose wiring and connectors in the sensor circuit
- Damaged or missing teeth on the reluctor ring (crankshaft tone wheel)
- Excessive debris or metal shavings on the magnetic tip of the sensor
- Incorrect sensor air gap (if adjustable)
- Faulty Powertrain Control Module (PCM) (rare)
What to check before replacing parts
Visually inspect the crankshaft position sensor, wiring harness, and connector.
Look for: Look for frayed wires, melted insulation, loose connections, or corrosion in the connector pins that could disrupt the signal.
Remove and inspect the crankshaft position sensor tip.
Look for: Check for a buildup of metal shavings, oil, or debris on the magnetic tip, which can interfere with the sensor's ability to read the reluctor ring.
Test the crankshaft position sensor resistance and voltage/ground supply using a digital multimeter.
Look for: Compare the resistance reading to the manufacturer's specifications. Ensure the sensor is receiving the correct reference voltage (usually 5V or 12V) and has a solid ground.
Monitor the crankshaft position sensor signal using an oscilloscope.
Look for: Observe the waveform while cranking or running the engine. Look for a consistent square wave (Hall effect) or AC sine wave (VR sensor) without dropouts, spikes, or irregularities.
Inspect the crankshaft reluctor ring (tone wheel) through the sensor mounting hole or by removing necessary components.
Look for: Check for broken, bent, or missing teeth, as well as excessive runout or damage that would cause an erratic signal to be generated.
This page explains the generic P0336 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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