GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The body control module (BCM) supplies battery voltage to the courtesy lamps, underhood lamp, instrument panel (I/P) compartment lamp, and both visor vanity mirror lamps. In the event that any of these lamps were to remain illuminated for more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the courtesy lamp supply voltage circuit to prevent a total battery discharge condition.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1480 Battery Rundown Protection Circuit

DTC Symptom

DTC Symptom Descriptor

00

Short to Ground

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

DTC B1480 will set when the courtesy lamp supply voltage circuit that feeds the courtesy lamps, underhood lamp, IP compartment lamp, console lamp and both visor vanity mirror lamps is shorted to ground for longer than 1 second.

Action Taken When the DTC Sets

The courtesy lamps, underhood lamp, I/P compartment lamp, and both visor vanity mirror lamps will not operate.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • You issue a scan tool CLEAR DTCs command.
    • A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Diagnostic Aids

Thoroughly inspect the wiring and connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis causing part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.

Is DTC B1480 displayed as current?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

Test the courtesy lamp supply voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 5

Go to Step 4

4

Replace the body control module (BCM). Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 5

--

5

  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