Important: If the crankshaft position variation learn procedure has not learned, a false misfire could be detected and DTC P0300 may set. If sent here from DTC P0300, proceed with the crankshaft position variation learn procedure.

1. Monitor the engine control module (ECM) for DTCs with a scan tool. If other DTCs are set, except DTC P0300, or P0315, refer to Diagnostic Trouble Code (DTC) List for the applicable DTC.
2. Select the crankshaft position variation learn procedure with a scan tool.
3. Follow the scan tool instructions.
4. The scan tool monitors certain component signals to determine if all the conditions are met to continue with the procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool monitors the following components:

•	Crankshaft position (CKP) sensors activity--If there is a CKP sensor condition, refer to the applicable DTC.

•	Camshaft position (CMP) signal activity--If there is a CMP signal condition, refer to the applicable DTC.

•	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.

5. Enable the CKP system variation learn procedure with the scan tool. Perform the following when the scan tool flashes Test in Progress:

5.1.	Accelerate to wide open throttle (WOT).

Important:     •  During the CKP variation learn procedure, the engine speed will fluctuate from approximately 1,000-4,500 RPM. If the engine speed exceeds 6,000 RPM at this time, fuel cutoff mode is not enabled and the throttle should be released immediately.    •  The ECM only allows 1 CKP variation learn procedure an ignition cycle. The ignition and the scan tool must be turned OFF for more than 30 seconds. If another CKP variation learn procedure is attempted without turning the scan tool and ignition OFF for 30 seconds, the scan tool flashes Accelerate to Wide Open Throttle. The engine speed will exceed 6,000 RPM and the CKP variation learn procedure will not be successful because fuel cutoff was not enabled.

5.2.	Hold the accelerator pedal in the fuel cutoff mode until the scan tool displays Learned This Ignition. It may take 5-8 seconds before the Learned This Ignition is displayed on the scan tool.

6. 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, refer to DTC P0315 . If any other DTCs set, refer to Diagnostic Trouble Code (DTC) List for the applicable DTC.
7. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.

The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether or not DTC P0315 is set: