GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The body control module (BCM) receives a ground signal from the door jamb or courtesy lamp switches requesting courtesy lamp illumination. When this occurs, the BCM directly sends a voltage through the courtesy lamp supply voltage circuit illuminating the courtesy lamps.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2615 Passenger Compartment Dimming 2 (courtesy lamps, etc.) Circuit

Conditions for Running the DTC

The battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

    • When the BCM receives a courtesy lamp illumination request signal and the courtesy lamp supply voltage circuit is shorted to ground.
    • When the BCM is not receiving a courtesy lamp illumination request signal and the courtesy lamp supply voltage circuit is shorted to voltage.
    • There is a loss of the rear fuse block TBC 3 battery supply voltage to the BCM for more than one second.

Action Taken When the DTC Sets

The courtesy 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.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step determines if an open or short to ground exists.

  2. This step determines if a short to ground exists in the lamp wiring or internally within the BCM.

  3. This test determines if an open exists in the TBC 3 battery positive voltage circuit, the courtesy lamp supply voltage circuit, or internally within the BCM.

  4. After replacement of the BCM you must calibrate the new module for proper operation.

Step

Action

Yes

No

Schematic Reference: Interior Lights 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

Inspect the TBC 3 fuse in the rear fuse block.

Is the fuse good?

Go to Step 4

Go to Step 3

3

Test the TBC 3 battery positive voltage and courtesy lamp supply voltage circuits for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 5

4

Test the TBC 3 battery positive voltage and courtesy lamp supply voltage circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 5

5

Inspect for poor connections at the harness connectors 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 7

Go to Step 6

6

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 7

--

7

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK