GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 Sunfire 🢒 DTC 🢒 DTC B2558

Circuit Description

The interior lamps consist of the dome lamp, courtesy lamps and the rearview mirror reading lamps. Battery voltage for the interior lamps is supplied by the BCM through the inadvertent power control circuit. The BCM controls the interior lamps by supplying ground to the courtesy lamp low control circuit. If the courtesy lamp low control circuit becomes shorted to voltage, DTC B2558 sets.

Conditions for Running the DTC

At least one 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

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

Test Description

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

  1. This step tests for an internally shorted IP dimmer switch.

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 instrument panel (IP) dimmer switch.
  3. Turn ON the ignition, with the engine OFF.
  4. Test the courtesy lamp low control circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is there a short to voltage?

Go to Step 4

Go to Step 5

4
  1. Turn OFF the ignition.
  2. Disconnect the body control module (BCM) connectors.
  3. Turn ON the ignition, with the engine OFF.
  4. Test the courtesy lamp low control circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is there a short to voltage?

Go to Step 7

Go to Step 6

5

Inspect for poor connections at the harness connector of the IP dimmer switch. 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 10

Go to Step 8

6

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 10

Go to Step 9

7

Repair the short to voltage in the courtesy lamp low control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 10

--

8

Replace the IP dimmer switch. Refer to Instrument Panel Lamp Dimmer Switch Replacement .

Did you complete the replacement?

Go to Step 10

--

9

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

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

Did you complete the replacement?

Go to Step 10

--

10
  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