B2646

Diagnostic Chart:

Schematics:

CIRCUIT DESCRIPTION
The ambient light sensor is a photo transistor that the output changes as the light level changes. The instrument panel module (IPM) determines the ambient light based on the voltage from the ambient light sensor. The IPM sends out a class 2 message to the dash integration module (DIM).

CONDITIONS FOR RUNNING THE DTC
The IPM is powered.

CONDITIONS FOR SETTING THE DTC
The feedback voltage is less than 0.09 V or greater than 4.75 V.

ACTION TAKEN WHEN THE DTC SETS
The IPM sets the ambient light status to DARK.

CONDITIONS FOR CLEARING THE DTC
The IPM does not detect a voltage that is less than or greater than the predetermined value during the diagnostic self test.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. This step tests the ambient light sensor signal circuit for an open, short to power or short to ground.
4. This step test the signal return circuit for an open or short to power.