B2648

Diagnostic Chart:

Schematics:

CIRCUIT DESCRIPTION
The ambient light sensor is a photo transistor that the output changes as the light level changes. The climate control panel module (CCP) determines the ambient light based on the voltage from the ambient light sensor. The CCP module controls the headlamp automatic, on/off and delayed off functions.

CONDITIONS FOR RUNNING THE DTC
^ The CCP is powered.
^ DTC B1327 is not current.

CONDITIONS FOR SETTING THE DTC
The feedback voltage is greater than 4.8 V for greater than 2 seconds.

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

CONDITIONS FOR CLEARING THE DTC
The CCP does not detect a voltage 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 ground, or short to power.
4. This step tests the signal return circuit for an open or short to power.