Crankshaft Position Sensor A Circuit Malfunction
The crankshaft position sensor (CKP) is not communicating properly with the engine control module, preventing accurate ignition timing and fuel injection control. Without valid crankshaft position data, the engine cannot start reliably or may stall without warning, creating a serious safety hazard.
What You Might Notice
- Engine will not start or starts intermittently
- Engine stalls while driving
- Severe hesitation or rough running
- Check engine light illuminated
- No spark or fuel delivery
Most Common Causes
- 1
Failed crankshaft position sensor
The CKP sensor has internally failed and is no longer producing a valid signal to the PCM. This is the most common cause of P0335.
- 2
Damaged CKP sensor connector or wiring
Corroded, loose, or damaged connector pins or wiring harness prevent the sensor signal from reaching the engine control module.
- 3
Damaged reluctor ring
Missing or broken teeth on the reluctor ring, or a sheared-off keyway preventing proper rotation, stops the sensor from detecting crankshaft position.
- 4
Broken timing belt or failed PCM
A broken timing belt prevents crankshaft rotation detection, or a faulty PCM fails to process the sensor signal correctly.
How to Diagnose It
- 1
Check Failed crankshaft position sensor — The CKP sensor has internally failed and is no longer producing a valid signal to the PCM. This is the most common cause of P0335.
- 2
Check Damaged CKP sensor connector or wiring — Corroded, loose, or damaged connector pins or wiring harness prevent the sensor signal from reaching the engine control module.
- 3
Check Damaged reluctor ring — Missing or broken teeth on the reluctor ring, or a sheared-off keyway preventing proper rotation, stops the sensor from detecting crankshaft position.
- 4
Check Broken timing belt or failed PCM — A broken timing belt prevents crankshaft rotation detection, or a faulty PCM fails to process the sensor signal correctly.
How to Fix It
- 1
Replace crankshaft position sensor
Remove the failed CKP sensor and install a new OEM or quality replacement sensor in the same location, ensuring proper torque and connector seating.
- 2
Repair CKP sensor wiring and connector
Inspect the sensor connector and wiring harness for corrosion or damage; clean corroded terminals with electrical contact cleaner, repair damaged wiring, or replace the entire connector assembly if needed.
- 3
Inspect and replace reluctor ring if damaged
Remove the crankshaft or camshaft to access the reluctor ring; if teeth are missing or it is not rotating freely, replace the ring or the component it is attached to.
- 4
Replace timing belt or PCM if necessary
If the timing belt is broken, replace it following manufacturer specifications; if the PCM is confirmed faulty through diagnostic testing, have it reprogrammed or replaced by a qualified technician.
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