GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The body control module (BCM) controls the courtesy lamps theater dimming. The BCM grounds the lamps directly. The ground will slowly reduce in order to turn the lamps to the OFF position. If there is a short to battery positive voltage condition in the interior lamp control circuit, DTC B2458 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2458 Interior Lamp Control Circuit High

Conditions for Setting the DTC

The BCM detects a short to battery positive voltage in the interior lamp control circuit for more than 0.15 seconds.

Action Taken When the DTC Sets

    • Stores DTC B2458 in the BCM memory.
    • No driver warning message will be displayed for this DTC.

Conditions for Clearing the DTC

    • A short to battery positive voltage is no longer detected by the BCM on the interior lamp control circuit.
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the fault is no longer present.

Test Description

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

  1. This step tests the interior lamp control circuit for a short to battery positive voltage.

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring 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

Test the interior lamp control circuit of the body control module (BCM) for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 5

Go to Step 3

3

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 5

Go to Step 4

4

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 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