Diagnostic Aids
WARNING: This page is about a different car, the 2001 GMC Savana, 2001 Chevrolet RV Cutaway, 2001 Chevrolet Cutaway, and 2001 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
If crankshaft position system variation learn procedure cannot be learned, check for the following conditions:
- A chipped or damaged reluctor wheel.
- Incorrect alignment of CKP sensor to reluctor wheel.
- Excessive crankshaft run-out.
- Interference in signal circuit to CKP sensor.
- Incorrect ratio of crankshaft to camshaft pulses.
Misfire diagnostic is not operable when engine speed is more than 1000 RPM and DTC P1336 is set.
When learn procedure is in progress and engine speed is at 4000 RPM, a decrease in engine speed will occur. During engine coast down, PCM monitors CKP sensor signal and stores pattern. This pattern is used to determine if the crankshaft speed variations are due to misfire.