B1802

DTC B1802 Courtesy Lamps Circuit:

CIRCUIT DESCRIPTION
The Body Control Module (BCM) controls the courtesy and convenience lamps. The BCM receives voltage from the INADV POWER BUS Fuse and controls the application of this voltage to the courtesy and convenience lamps through a relay internal to the BCM. If the BCM detects a short to ground, a fault condition is present and a DTC will set.

CONDITIONS FOR SETTING THE DTC
^ BCM detects a short to ground in circuit 1732.
^ BCM is shorted to ground internally.
^ All conditions must be present for more than 0.1 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ Stores a DTC B1802 in the BCM memory.
^ No driver warning message will be displayed for this DTC.

CONDITIONS FOR CLEARING THE DTC
^ Under all fault conditions, the ignition switch must be cycled from the OFF position to the RUN position before this DTC can change from current to history.
^ The BCM no longer sees a short to ground in circuit 1732 when the ignition switch is in the RUN position.
^ A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ Using a scan tool.

DIAGNOSTIC AIDS
^ The following conditions may cause an intermittent malfunction to occur:
- An intermittent short to ground in circuit 1732.
^ If any of the courtesy lamps connected to circuit 1732 are shorted to ground.
^ If the BCM is shorted to ground internally.
^ If the DTC is a history DTC, the problem may be intermittent. Try performing the tests shown while moving 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 B1802.
2. Determines if there is a short to ground in circuit 1732.
4. Clears BCM DTCs and checks for BCM DTC B1802 again.