GM Service Manual Online
For 1990-2009 cars only

Circuit Description

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

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2615 Passenger Compartment Dimming 2 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 or open only to the first splice from the BCM.
    • There is a loss of the rear fuse block truck body controller (TBC) 3 battery supply voltage to the BCM for more than 1 second.

Action Taken When the DTC Sets

The courtesy/dome 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 .
    • Only an open circuit up to the first splice from the BCM will set DTC B2615.

Test Description

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

  1. This step test determines if the problem exists in the wiring.

  2. This step test determines if an open exists in the body wiring harness extension harness.

  3. 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 Data Communication Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Test the courtesy lamps supply voltage circuit for an open, high resistance, short to voltage, or short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 8

Go to Step 3

3

Test the truck body controller (TBC) 3 battery positive supply voltage circuit within the body wiring harness extension harness for continuity. Refer to Circuit Testing .

Is continuity present?

Go to Step 4

Go to Step 5

4

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 .

Did you find and correct the condition?

Go to Step 8

Go to Step 7

5

Inspect for poor connections at the body wiring harness extension harness connectors. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 8

Go to Step 6

6

Replace the body wiring harness extension harness to the BCM. Refer to Body Control Module Body Wiring Harness Extension Harness Replacement for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 8

--

7

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 8

--

8

  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