B2646

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The ambient light sensor is a light sensitive diode. The instrument panel integration 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
This test is run every 150 milliseconds.

CONDITIONS FOR SETTING THE DTC
The ambient light sensor voltage is less than 0.09 or greater than 4.75V on 3 consecutive tests.

CONDITIONS FOR CLEARING THE DTC
Ambient light status set to "DARK".

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

DIAGNOSTIC AIDS
^ The following may cause an intermittent:
- Bent terminal
- Backed out terminal
- Damaged terminal
- Poor terminal tension
- Chafed wire
- Broken wire inside the insulation
^ When diagnosing for an intermittent short or an open, manipulate the wire harness while watching the test equipment for changes.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the high voltage range.
4. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.