Code P041, No Cam Reference Sens SGNL From IGN Control Module: Action

PCM turns on MIL.

1. Checks if Code P035 is set because a REF LO problem can cause other ignition problems.
2. Checks resistance of camshaft position sensor. Resistance should be 800-1200 ohms. If resistance is greater, check for an open circuit. If resistance is less, check for a short.
3. Checks if circuits No. 632 or 633 is shorted to ground.
4. Checks if sensor is able to produce a DC voltage greater than 0.2 volt. If it can, sensor is okay.
5. A reading of 4 Hertz with engine running means that ignition control module is producing cam pulses.
6. Checks if circuit is at fault or if ICM is faulty.

Fig 1: Code P041 Schematic, No CAM Reference Sensor Signal From Ignition Control Module

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P041 Diagnostic Flow Chart, No CAM Reference Sensor Signal From Ignition Control Module

Courtesy of GENERAL MOTORS CORP.