P0336 on the 6.7L Cummins is a crankshaft position (CKP) sensor A range or performance fault. The CKP sensor reads a toothed target on the crankshaft so the ECM knows engine speed and position for fuel timing. P0336 sets when the signal is present but irregular, with missing or extra pulses or a pattern the ECM cannot reconcile, which can cause stalling and hard starting.
The crankshaft signal is fundamental to running the engine, so any inconsistency in it gets the ECM's attention immediately. Unlike a complete loss of signal, P0336 means the sensor is working but producing a flawed pattern, which often points to an air gap problem, a damaged tone ring, or a marginal sensor. Because the symptoms can be intermittent, careful diagnosis with live data saves guesswork.
What P0336 means
The ECM expects a clean, evenly spaced pulse train from the CKP sensor as the crank turns. P0336 flags a rationality problem: the pulses are irregular, there are missing or extra teeth in the signal, or it does not correlate with the camshaft sensor. This differs from a circuit code because the signal exists but is not trustworthy.
Common causes
- Failing or marginal crankshaft position sensor
- Incorrect sensor air gap or a loose sensor
- Damaged or debris-fouled crankshaft tone ring
- Metal debris on the sensor tip
- Wiring or connector fault causing signal noise
Symptoms
- Hard starting or intermittent no-start
- Stalling, sometimes while driving
- Rough running or hesitation
- Check engine light with P0336 stored
- Possible correlation codes with the cam sensor
How to diagnose it
Inspect the CKP sensor and its mounting first, confirming it is tight and undamaged. Remove it and check the tip for metal debris and the correct condition. With a scan tool, monitor engine RPM while cranking and running; a dropout or erratic RPM signal points to the sensor or tone ring. Inspect the connector and wiring for corrosion, chafing, and a secure fit, and check for signal noise from a nearby ground or shielding fault. If the wiring and gap are good and the signal is still irregular, the sensor is the likely cause.
How to fix it
Clean debris from the sensor tip and set the correct air gap if the sensor is adjustable, then secure the mounting. Repair corroded connectors and damaged wiring. If the sensor is marginal or the signal remains irregular with good wiring, replace the crankshaft position sensor. If the tone ring is damaged, it must be addressed as well. After the repair, clear the code, confirm a stable RPM signal while cranking and running, and road test. For the correct CKP sensor for your 6.7L Cummins, contact sales@coredieselparts.com.
Frequently asked questions
Can a 6.7L Cummins run with P0336?
It may run but expect hard starts, stalling, or rough running. Because the crank signal is essential to timing, repair it promptly to avoid being stranded.
What is the difference between P0335 and P0336?
P0335 is a crankshaft sensor circuit fault, often no signal at all, while P0336 means the signal is present but irregular. Both point to the sensor, wiring, or tone ring.
Can metal debris on the sensor cause P0336?
Yes. Metal filings collect on the magnetic tip and distort the signal pattern. Cleaning the tip and checking the air gap is a good first step.
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