B2613

CIRCUIT DESCRIPTION
The Body Control Module (BCM) monitors the instrument panel (IP) dimming voltage on the instrument panel lamp fuse supply voltage 2 circuit from the dimmer switch, or thumb wheel, part of the headlamp and panel dimmer switch. The dimmer switch controls the IP dimming by sending a signal to the BCM on the instrument panel lamp fuse supply voltage 2 circuit in order to indicate the position of the thumb wheel when the headlamps are ON. The dimmer switch also provides dimming for the backlighting of the instrument cluster, radio and the overhead console.

CONDITIONS FOR RUNNING THE DTC
- The battery voltage must be between 9 and 16 volts.
- Ignition switch in the RUN position.
- The park lamp switch, which is part of the headlamp and panel dimmer switch, must be in the OFF or AUTO position and the ambient light sensor must be in the DARK state.
- The park brake released.

CONDITIONS FOR SETTING THE DTC
To set B2613, the following conditions must be present:
- The instrument panel lamp fuse supply voltage 2 circuit is shorted to battery voltage.
- The above conditions must be met for 0.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
The instrument panel lights remain full bright at all times.

CONDITIONS FOR CLEARING THE MIL/DTC
- A current DTC will clear at the next fault free ignition cycle.
- A history DTC will clear after 100 consecutive ignition cycles without a fault present.
- Use a scan tool in order to clear history and current DTCs.

DIAGNOSTIC AIDS
Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent and Poor Connections in Diagrams.

TEST DESCRIPTION

Steps 1-3:

Steps 4-14:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the low voltage range.
4. Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
5. Tests for a short to voltage in the 12 volt reference circuit.
13. After replacement of the BCM you must calibrate the new module for proper operation.