B2558

Diagnostic Chart:

Schematics:

CIRCUIT DESCRIPTION
The interior lamps controlled by the BCM 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 output (circuit 1732) which is internal to the BCM. The interior lamps are controlled by the body control module (BCM) by grounding circuit 156. If circuit 156 becomes shorted to battery voltage, DTC B2558 sets.

CONDITIONS FOR RUNNING THE DTC
The interior lamps are commanded on by the BCM.

CONDITIONS FOR SETTING THE DTC
The interior lamp control circuit (56) is shorted to battery positive voltage for 5 second.

ACTION TAKEN WHEN THE DTC SETS
The BCM disables the interior lamp control output for the remainder of the ignition cycle.

CONDITIONS FOR CLEARING THE DTC
^ A current DTC B2558 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 during the 100 ignition cycles.

DIAGNOSTIC AIDS
If the DTC is a history DTC, the problem may be intermittent. Try the 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.