GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The interior lamps consist of the dome lamp, courtesy lamps and the rearview mirror reading lamps. The body control module (BCM) supplies battery positive voltage to the interior lamps through the inadvertent power control relay. The BCM controls the interior lamps by grounding the interior lamps control circuit. If the interior lamps control circuit becomes shorted to voltage, DTC B2558 sets.

Conditions for Running the DTC

At least 1 of the following conditions must exist:

    • At least one door is open.
    • The interior lamps are commanded on by the BCM.

Conditions for Setting the DTC

    • The interior lamps are commanded on by the BCM.
    • The interior lamp control circuit is shorted to battery positive voltage for 125 milliseconds.

Action Taken When the DTC Sets

    • DTC B2558 is stored in the BCM memory.
    • The BCM disables the interior lamp control output for the remainder of the ignition cycle.

Conditions for Clearing the DTC

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

Diagnostic Aids

  1. If the DTC is a history DTC, the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. When DTC 2558 is current, the interior lamps are inoperative. After repairing the fault, the ignition must be cycled before the interior lamps will illuminate.

Test Description

The number below refers to the step number on the diagnostic table.

  1. The normal state of the INTERIOR LAMP OUTPUT parameter with a door open is ON.

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the courtesy lamps on and off.

Do the courtesy lamps turn on and off with each command?

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

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the BCM connectors.
  3. Turn ON the ignition, with the engine OFF.
  4. Test the control circuit of the interior lamps for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 6

Go to Step 4

4

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 6

Go to Step 5

5

Important: Perform the set up procedure for the body control module.

Replace the body control module. Refer to Body Control Module Replacement .

Did you complete the replacement?

Go to Step 6

--

6

  1. Use the scan tool in order to clear the DTCs.
  2. Cycle the ignition.
  3. 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