LaCrosse V6-3.8L (2009)
Crankshaft Position Sensor: Service and Repair
Crankshaft Position System Variation Learn
Crankshaft Position System Variation Learn
Important: The Crankshaft Position (CKP) system variation learn procedure is also required when the following service procedures have been
performed, regardless of whether DTC P0315 is set:
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An engine replacement
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A control module replacement
*
A crankshaft balancer replacement
*
A crankshaft replacement
*
A CKP sensor replacement
*
Any engine repairs which disturb the crankshaft to CKP sensor relationship.
Important: The control module monitors certain component signals to determine if all the conditions are met to continue with the CKP System
Variation Learn Procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool displays the signals of the
following components:
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CKP sensors activity-If there is a CKP sensor condition, refer to the applicable DTC that set.
*
Camshaft position (CMP) signal activity-If there is a CMP signal condition, refer to the applicable DTC that set.
*
Engine coolant temperature (ECT)-If the engine coolant temperature is not warm enough, idle the engine until the engine coolant
temperature reaches the correct temperature.
1. Install a scan tool.
2. Monitor the powertrain control module (PCM) for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to Diagnostic Trouble
Code (DTC) List - Vehicle (See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions) for the
applicable DTC that set.
3. With a scan tool, select the CKP System Variation Learn Procedure and perform the following:
1. Block drive wheels.
2. Set parking brake.
3. DO NOT apply brake pedal.
4. Cycle ignition from OFF to ON.
5. Apply and hold brake pedal for the duration of the procedure.
6. Start and idle engine.
7. Turn the air conditioning (A/C) OFF.
8. The vehicle must remain in Park or Neutral.
Important: While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine
control is returned to the operator and the engine responds to throttle position after the learn procedure is complete.
9. Accelerate to wide open throttle (WOT) and release when the fuel cut-off occurs.
4. The scan tool displays Learn Status: Learned this Ignition. If the scan tool indicates that DTC P0315 ran and passed, the CKP variation learn
procedure is complete. If the scan tool indicates DTC P0315 failed or did not run, or another DTC is present, refer to Diagnostic Trouble Code
(DTC) List - Vehicle (See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions) and perform the
appropriate diagnostic procedure.
5. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully in order to store the CKP system variation values in the
PCM memory.
