B2558

Diagnostic Chart:

Schematic:

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 relay (internal to the BCM) output. The interior lamps are controlled by the body control module (BCM) by grounding the interior lamps control circuit. If the interior lamps control circuit becomes shorted to battery 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
^ A current DTC B255B will clear when the malfunction is no longer present and the ignition switch is cycled.
^ All BCM history codes clear after 100 ignition cycles with no current codes active within the 100 ignition cycles.

DIAGNOSTIC AIDS
If the DTC is a history DTC, the problem may be intermittent. Try performing tests while wiggling the wiring and connectors. This can often cause the malfunction to appear.

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
2. The normal state of the INTERIOR LAMP OUTPUT parameter with a door open is ON.
3. The normal state of the INTERIOR LAMP OUTPUT parameter with all doors closed is OFF.