Possible Causes
NOTE: The listed causes may not be a complete list of all potential issues and there may be other causes.
- Faulty crankshaft position sensor
- Crankshaft position sensor harness is open or shorted
- Poor electrical connection in crankshaft position sensor circuit
- Signal plate may be damaged
Description
The crankshaft position sensor (CKP) sends pulses to the powertrain control module (PCM) when the teeth of the reluctor wheel rotate past the CKP sensor. The PCM uses CKP pulses to synchronize ignition and fuel injector operation, and to time the interval between each CKP pulse. The PCM determines when excessive crankshaft speed variation occurs by comparing each new time interval with the previous interval. A misfire causes an unexpected change in crankshaft speed. Some acceleration/deceleration is expected between each firing event, but if crankshaft speed changes more than expected, the PCM interprets this as a misfire. The interval between CKP sensor pulses is extremely small.
How to Repair
Check the “Possible Causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
- Engine light on (or service engine soon warning light)
- Lack/loss of power
- Engine stalling
- Engine hard to start