B2458

DTC B2458 Theater Dimming 2 Circuit:

CIRCUIT DESCRIPTION
The Body Control Module (BCM) controls the LH and RH reading rail courtesy/reading lamps and the dome lamp for theater dimming. The BCM grounds the lamps directly and the output shall turn the lamps off by fading out. If there is a short to voltage in circuit 157, a fault condition is present and a DTC will set.

CONDITIONS FOR SETTING THE DTC
^ The BCM detects a short to voltage in circuit 157 for more than 0.15 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ Stores a DTC B2458 in the BCM memory.
^ No driver warning message will be displayed for this DTC.

CONDITIONS FOR CLEARING THE DTC
^ A short to voltage is no longer detected by the BCM in circuit 157.
^ A history DTC will clear after 100 consecutive ignition cycles if the condition for the fault is no longer present.
^ Using a scan tool.

DIAGNOSTIC AIDS
^ The following conditions may cause an intermittent malfunction to occur:
- An intermittent short to voltage in circuit 157.
- A short to voltage internal to the BCM.
^ If the DTC is a history DTC, the problem may be intermittent. Try performing the tests shown while wiggling wiring and connectors, this can often cause the malfunction to appear.
^ DTC P1626 will set in the Powertrain Control Module (PCM) when the ignition switch is in the RUN position with the BCM disconnected.

TEST DESCRIPTION
Numbers below refer to the step numbers on the diagnostic table.
1. Always perform the BCM Diagnostic System Check before attempting to diagnose a DTC B2458.
2. If BCM DTC B0828 sets perform B0828 diagnostic table.
3. Checks for a short to voltage in circuit 157.
5. Clears BCM DTCs and checks for BCM DTC B2458 again.