B0951

DTC B0951

CIRCUIT DESCRIPTION
The body control module (BCM) controls the illumination dimming of all of the control switch indicators. The BCM will set the control switch indicator illumination level according to the instrument panel (I/P) dimmer switch signal received when the component is activated and the indicator is ON.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:

DTC B0951 Headlamps On Indicator Circuit

CONDITIONS FOR RUNNING THE DTC
The battery voltage must be between 9-16 volts.

CONDITIONS FOR SETTING THE DTC
- The LED dimming signal circuit is open.
- The LED dimming signal circuit is shorted to ground.
- The LED dimming signal circuit is shorted to voltage.
- There is a loss of the rear fuse block truck body controller (TBC) 5 battery supply voltage to the BCM for more than 1 second.

ACTION TAKEN WHEN THE DTC SETS
The control switch indicators will not operate or will not dim.

CONDITIONS FOR CLEARING THE MIL/DTC
- This DTC will clear on current status after the condition for setting the fault is corrected.
- A history DTC will clear after 100 consecutive ignition cycles without a fault present.
- History and current DTCs can be cleared using a scan tool.

TEST DESCRIPTION

Step 1 - Step 12:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for an open in the TBC 5 battery positive voltage supply circuit within the body wiring harness extension harness.
4. Tests for voltage at the LED dimming signal circuit.
5. Tests for voltage at the LED dimming signal circuit when the headlamp switch is in the OFF position.
11. After replacement of the BCM, you must calibrate the new module for proper operation.