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 body control module (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.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2558 Passenger Compartment Lamp Control Circuit High
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.
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 |
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 |
Is there a short to voltage? | Go to Step 4 | Go to Step 5 | |
4 |
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 I/P 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 I/P dimmer switch. Refer to Instrument Panel Lamp Dimmer Switch Replacement . Did you complete the replacement? | Go to Step 10 | -- |
9 | 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 10 | -- |
10 |
Does the DTC reset? | Go to Step 2 | System OK |
