P1398 Misfire Adaptive Numerator at Limit
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P-1398 MIS-FIRE ADAPTIVE NUMERATOR AT LIMIT
WHEN MONITORED
Under closed throttle deceleration; A/C off; engine coolant temp above 75 deg; longer than 50 seconds after engine start. Speed at which deceleration occurs must be sufficient for given gear range; eg, above 36 mph in 1st gear or above 65 mph in high gear.
SET CONDITION
When one of the CKP sensor target windows (40 degrees) has more than 2.86% variance from the reference window.
POSSIBLE CAUSES
- Slots in flexplate defective
- CKP sensor defective
- CKP sensor not properly installed
- CKP sensor visibly defective
- Notches in crankshaft defective