CASE Relearn

A replacement ECM needs to learn the variability of the Crankshaft Position Sensor vs the Camshaft Position Sensor to accurately detect misfire conditions. This is performed after the VATS relink is completed. The engine will run at this point, but the Check Engine Light (CEL) will be illuminated until the CASE relearn is completed. A scan tool capable of performing this learn procedure is required. Refer to the scan tool and vehicle service manual for specific procedures, but typical steps expected are: 

1. Block drive wheels. 

2.  Apply parking brakes. 

3. Cycle ignition on and off.

4. Apply and hold brake pedal. NOTE: Some applications require that you NOT hold the brake pedal. Follow instructions on scan tool. 

5. Start engine. 

6. Turn off A/C. 

7. Place transmission in Park (automatic) or Neutral (manual). 

8. Increase engine RPM to value indicated on scan tool. 

9. Release throttle when fuel cut-off occurs, or if RPM value is exceeded. 

10. Verify the CEL is extinguished. Procedure is complete.