GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The courtesy lamp supply voltage circuit is controlled by the body control module (BCM). Should any device controlled by this circuit remain ON after the ignition key is removed, the BCM will turn inadvertent power OFF after 20 minutes to conserve battery energy.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1482 Battery Rundown Protection Circuit Low.

Conditions for Running the DTC

The interior lamps are active.

Conditions for Setting the DTC

Any of the following conditions will set this DTC:

    • The courtesy lamp supply voltage circuit is shorted to ground.
    • The battery positive voltage circuit to the BCM from the INT LTS/ONSTAR fuse is open or shorted to ground.

Action Taken When the DTC Sets

Interior lamps are inoperative.

Conditions for Clearing the DTC

    • The BCM receives the clear code command from the scan tool.
    • A current DTC will clear when the conditions for setting the DTC are no longer present.
    • A history DTC clears after 100 malfunction free ignition cycles.

Diagnostic Aids

If the DTC is a history DTC, the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Place the dome lamp in the ON position.

Does the dome lamp illuminate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Test the battery positive voltage circuit of the body control module (BCM) for an open, high resistance, or 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 4

4

Test the courtesy lamp supply voltage circuit for an open, high resistance, or 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

5

Inspect for poor connections at the harness connector of the 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

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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