Test Description
The numbers below refer to the step numbers on the diagnostic table.
Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
The Lighting Systems Symptoms will determine the correct diagnostic procedure to use when no DTCs are present.
The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
DTC B1000 and DTC B1001 are internal BCM malfunctions and should be corrected before performing any other diagnostic procedure.
Scheme 69
Scheme 70
Scheme 71
The numbers below refer to the step numbers on the diagnostic table.
Listen for an audible click when the fog lamp relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
Tests for voltage at the coil side of the fog lamp relay.
Verifies that the body control module is providing ground to the fog lamp relay.
Tests if ground is constantly being applied to the fog lamp relay.
Scheme 72
Scheme 73
The numbers below refer to the step numbers on the diagnostic table.
- Listen for an audible click when the fog lamp relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
- Tests for voltage at the coil side of the fog lamp relay.
- Verifies that the body control module is providing ground to the fog lamp relay.
Scheme 74
The number below refers to the step number on the diagnostic table.
- This step tests for an internally shorted IP dimmer switch.
Scheme 75
The numbers below refer to the step numbers on the diagnostic table.
- DTC B2600 will disable the daytime running lights (DRL). If the DRLs are operational the code is not current. If DTC B2600 is not current, Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems.
- This condition indicates that there is a short to voltage in the headlamp high beam signal circuit or the headlamp low beam signal circuit.
- This step verifies normal headlamp operation.
- This step checks for battery positive voltage at the coil side of the DRL relay.
- This step verifies that the body control module (BCM) is providing ground to the coil side of the DRL relay.
Scheme 76
Scheme 77
The numbers below refer to the step numbers on the diagnostic table.
- This step determines if a short to ground in the DRL relay control circuit or an open or high resistance in the left hand headlamp supply voltage circuit is causing DTC 2601 to set. A short to ground in the DRL relay control circuit will cause the DRLs to be on in this step. An open or high resistance in the left hand headlamp supply voltage circuit will cause the DRLs to not be illuminated in this step.
- This step determines if the BCM has an internal short to ground.
Scheme 78
The numbers below refer to the step numbers on the diagnostic table
Listen for an audible click when the DRL relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
Tests for voltage at the coil side of the DRL relay.
Verifies that the body control module is providing ground to the DRL relay.
Tests if ground is constantly being applied to the DRL relay.
Scheme 79
Scheme 80
The numbers below refer to the step numbers on the diagnostic table.
The normal operating voltage of the instrument panel dimmer switch is 0.5-11.5 volts.
If the value is above 11.5 volts, with the sensor disconnected, an open or short to voltage exists. If the value is below 0.5 volts, a short to ground exists.
