Crankshaft Position Sensor Performance

What P0336 means

The crankshaft position sensor (CKP) monitors a toothed reluctor plate mounted on the crankshaft. As each tooth passes the sensor's pickup coil, an AC voltage pulse is induced. The ECM counts the pulses per revolution and uses this data to calculate engine speed and crankshaft position for fuel injection timing and ignition control. Unlike P0335 (which fires when the signal is absent entirely), P0336 is a range and performance fault — the sensor is producing a signal, but the pulse count per revolution falls outside the acceptable window. The ECM stores P0336 when it receives fewer than the expected minimum or more than the expected maximum pulses within a defined monitoring interval — a pattern that cannot result from normal engine operation and therefore indicates a sensor gap problem, a damaged or cracked reluctor tooth, electromagnetic interference from a deteriorating sensor coil, or an intermittent wiring fault that causes extra or missing pulses. This is a 1-trip code requiring the VVT sensor circuit to be confirmed functional before the crank sensor rationality check runs.

Symptoms

• Check engine light on — 1-trip code
• Engine stalling or misfiring under load — erratic crank signal causes injection timing errors
• Hard starting or no-start in severe cases when signal corruption prevents the ECM from establishing synchronization
• Rough running and hesitation — missed or extra pulses cause timing advance/retard errors
• Random misfires across cylinders (may accompany P0300 random misfire code) when the crank position data is intermittently corrupted

Common causes

• Excessive air gap between the crankshaft position sensor tip and reluctor ring teeth — gap should be within factory specification (typically 0.5–1.5 mm depending on application)
• Cracked, chipped, or deformed reluctor ring tooth — a damaged tooth produces an irregular pulse width that the ECM counts as an extra or missing signal
• Weakened or partially demagnetized crankshaft position sensor — the pickup coil generates weaker pulses that partially merge or split as they pass the ECM detection threshold
• Intermittent wiring fault in the NE+ or NE- circuit — a partially broken wire creates sporadic noise on the signal line
• Loose sensor mounting — the sensor is not fully seated and vibrates, varying the air gap dynamically

Severity & driving advice

Severity: high — Erratic crank signal causes misfires, stalling, and potential no-start. Engine timing accuracy depends on this sensor. Repair promptly.

Can I drive? Not safe with active symptoms. Repair first.

Diagnostic approach

1. Check for companion codes before testing the sensor — VVT sensor codes (P0340, P0342, P0343, P0345) disable the crank position rationality check. Clear and verify which code is primary. If VVT sensor codes are present, address those first — P0336 may resolve without touching the crank sensor.
2. Inspect sensor installation and check for physical damage — Remove the crankshaft position sensor. Inspect the sensor tip for debris and the reluctor ring teeth through the access opening. Look for metallic debris stuck to the sensor tip, chipped or bent teeth on the reluctor ring, or rust buildup altering the effective air gap. The sensor should seat fully in its bracket with no wobble — a loose sensor vibrates and varies the air gap dynamically.
3. Inspect all reluctor ring teeth for damage — Using a flashlight or borescope, rotate the engine slowly by hand (using a socket on the crank bolt) and inspect every tooth of the reluctor plate. A cracked or missing tooth will produce an abnormal pulse that the ECM cannot rationalize. Even a slight burr or chip can produce double-pulses at high speed and cause P0336.
4. Test crank sensor resistance — Disconnect the crankshaft position sensor connector. Measure resistance across the two signal terminals of the sensor (NE+ and NE-). On a typical inductive-type sensor, resistance should fall within the manufacturer's specification — commonly 1,000–2,500 Ω at room temperature. A reading outside this range or an open circuit indicates a failed sensor coil.
5. Test the wiring harness between sensor and ECM — With the sensor and ECM connectors both disconnected, measure resistance between the NE+ pin at the sensor harness connector and the corresponding NE+ pin at the ECM connector — should be below 1 Ω. Repeat for NE-. Then check NE+ to body ground and NE- to body ground — both should be 10 kΩ or higher to confirm no short to ground.
6. View the sensor waveform on an oscilloscope — Connect an oscilloscope between the NE+ and NE- terminals at the ECM connector with the engine idling. The waveform should display evenly spaced pulses at consistent amplitude. Missing pulses, extra spikes, or varying amplitude pulses identify the fault source — damaged tooth, bad sensor, or wiring noise. Set scope to 5 V per division and 20 ms per division for a clear idle-speed waveform.

Typical repair costs

Make & model notes

Toyota: On Toyota 1GR-FE V6 engines (FJ Cruiser, 4Runner, Tacoma), the crank sensor uses a 34-tooth reluctor integrated onto the crankshaft. Sensor replacement requires removing the lower timing cover access panel — allow extra labour time. Reluctor tooth damage is uncommon but can occur after a front engine-mount failure allows excessive crankshaft movement.

GM: GM LS V8 engines (5.3L, 6.0L, 6.2L) use a 58-tooth reluctor on Generation IV engines. P0336 on LS engines is often preceded by stalling complaints that disappear at highway speed — the increased reluctor rotational speed improves signal strength at high RPM, masking a weak sensor that is borderline at low speed.

Ford: Ford Modular V8 (4.6L, 5.4L) and Coyote 5.0L engines use a 35-1 trigger wheel. P0336 on these platforms is frequently caused by a loose or improperly torqued sensor — the mounting flange is thin and can crack if overtightened. Always verify proper torque (typically 9–12 Nm) when replacing the sensor.

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