Circuit Description
The body control module (BCM) receives a variable voltage signal from the instrument panel (I/P) dimmer switch requesting to illuminate the instrument panel controls illumination lamps to a desired intensity. When this occurs, the BCM directly sends a variable voltage based on the I/P dimmer switch position on the backlight lamps control circuit, instrument panel lamps dimming control circuit, and the LED dimming signal circuit.
Voltage for the backlight lamps control circuit, instrument panel lamps dimming control circuit, and the LED dimming signal circuits is from the TBC 3 fuse 16 in the underhood fuse block directly through the BCM to these circuits.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2610 Passenger Compartment Dimming 1 Circuit
Conditions for Running the DTC
The battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
| • | The backlight lamps control circuit is open, shorted to ground, or shorted to battery positive voltage. |
| • | The I/P lamps dimming control circuit is open, shorted to ground, or shorted to battery positive voltage. |
| • | The LED dimming signal circuit is shorted to ground. |
| • | There is a loss of the underhood fuse block TBC 3 battery supply voltage to the BCM for 1 second. |
Action Taken When the DTC Sets
The I/P illumination lamps and the controls illumination lamps will not operate or are always ON.
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. |
Diagnostic Aids
| • | Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | A short to ground in the following circuits will cause the TBC 3 fuse to open: |
| - | The backlight lamps control |
| - | The instrument panel lamps dimming control |
| - | The LED dimming signal |
| - | Battery positive voltage from the underhood fuse block TBC 3 fuse |
| • | An open in the TBC 3 fuse will cause the BCM to set the following DTC: |
| - | B0951 |
| - | B2610 |
| - | B2625 |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step test determines if the problem exists in the headlamp switch or the BCM.
-
After replacement of the BCM, you must calibrate the new module for proper operation.
Step | Action | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Interior Lights Dimming Schematics Connector End View Reference: Lighting Systems Connector End Views or Computer/Integrating Systems Connector End Views in Computer/Integrating Systems | |||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||||
2 | Is the TBC 3 fuse in the underhood fuse block open? | Go to Step 3 | Go to Step 4 | ||||||||
3 | Test the following circuits for a short to ground:
Did you find and correct the condition? | Go to Step 11 | Go to Step 8 | ||||||||
4 | Test the backlight lamps control circuit and the I/P lamps dimming control circuit for the following:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 5 | ||||||||
Does the test lamp illuminate? | Go to Step 6 | Go to Step 7 | |||||||||
6 | Inspect for poor connections at the harness connector of the headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 9 | ||||||||
7 | Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 10 | ||||||||
8 | Repair the battery positive voltage circuit of BCM from the TBC 3 fuse in the underhood fuse block. Did you complete the repair? | Go to Step 11 | -- | ||||||||
9 | Replace the headlamp and panel dimmer switch. Refer to Headlamp Switch Replacement . Did you complete the replacement? | Go to Step 11 | -- | ||||||||
Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 4 | -- | |||||||||
11 |
Does the DTC reset? | Go to Step 2 | System OK | ||||||||
