Cutlass V6-191 3.1L VIN M SFI (1998)
Crankshaft Position Sensor: Service and Repair
Crankshaft Position System Variation Learn Procedure
The crankshaft position system variation compensating values are stored in the PCM non-volatile memory after a learn procedure has been performed. If
the actual crankshaft position system variation is not within the crankshaft position system variation compensating values stored in the PCM, DTC P0300
may set (refer to DIAGNOSTIC AIDS for DTC P0300).
The Crankshaft Position System Variation Learn Procedure should be performed if any of the following conditions are true:
^
DTC P1336 is set.
^
The PCM has been replaced.
^
The PCM has been reprogrammed.
^
The engine has been replaced.
^
The crankshaft has been replaced.
^
The crankshaft harmonic balancer has been replaced.
^
The crankshaft position sensor has been replaced.
CAUTION: Set the vehicle parking brake and block the drive wheels when performing the Crankshaft Position System Variation Learning
Procedure in order to prevent personal injury. Release the throttle immediately when the engine starts to decelerate. Once the learn procedure
is completed, the PCM will return the engine control to the operator and the engine will respond to the throttle position.
IMPORTANT: The scan tool crankshaft position system variation learn function will be inhibited if engine coolant temperature is less than 70°C (158°
F). Allow the engine to warm to at least 70°C (158°F) before attempting the crankshaft position system variation learn procedure.
The scan tool crankshaft position system variation learn function will be inhibited if any Powertrain DTCs other than DTC P1336 are set before or
during the crankshaft position system variation learn procedure. Diagnose and repair any DTCs if set. The crankshaft position system variation learn
function will be inhibited if the PCM detects a malfunction involving the camshaft position signal circuit, the 3X reference circuit, or the 24X reference
circuit.
^
If the scan tool indicates a problem with the Cam signal, refer to DTC P0341 CMP Sensor Circuit Performance.
^
If the scan tool indicates a problem with the 3X crank signal, refer to DTC P1374 3X Reference Circuit.
^
If the scan tool indicates a problem with the 24X crank signal, refer to DTC P0336 24X Reference Signal Circuit.
The scan tool crankshaft position system variation learn function will not be enabled until engine coolant temperature reaches 70°C (156°F).
Selecting the crankshaft position system variation learn procedure on the scan will command the PCM to enable CKP system variation learn fuel cutoff
and allow the crankshaft position system variation compensating values to be stored in the PCM. The PCM must detect an engine speed of 5150 rpm
(CKP system variation learn fuel cutoff) during the crankshaft position system variation learn procedure to store the crankshaft position system variation
