B2453

DTC B2453 Theater Dimming 1 Circuit Shorted To Voltage:

DTC B2453 Theater Dimming 1 Circuit Shorted To Voltage (Part 1 Of 2):

DTC B2453 Theater Dimming 1 Circuit Shorted To Voltage (Part 2 Of 2):

CIRCUIT DESCRIPTION
The Body Control Module (BCM) controls interior illumination. The BCM turns on the I/P and door courtesy lamps when:
^ Any vehicle door is opened.
^ The IP dimmer switch is in the DOME position.
^ During exit illumination or delayed illumination.
^ When unlocking the doors using the keyless entry transmitter.

The BCM turns off these lamps when all doors are closed and the IP dimmer switch is off.

All vehicle doors contain a door lock ajar switch. When the drivers door is open, the LF door lock ajar switch closes and sends a ground signal to the BCM through circuit 49. When one of the LF, RF, LR or RR door is open, its corresponding door lock ajar switch closes and sends a ground signal to the BCM through circuit 727. The BCM grounds circuit 156 when detecting a ground signal in either circuit 49 or 727.

When the driver's door is closed, the LF door lock ajar switch opens circuit 49. When the LF, RF, LR and RR doors are closed, their corresponding door lock ajar switches open circuit 727. The BCM then opens circuit 156 when either circuit 49 or 727 is open.

The BCM uses the voltage in circuit 240 to power the courtesy lights through circuit 1732. The BCM controls the power supplied in circuit 1732 for inadvertent load (battery rundown) protection. The BCM opens circuit 156 when the inadvertent load (battery rundown) protection is active (circuit 1732 is open.)

CONDITIONS FOR SETTING THE DTC
The BCM detects a short to B+ in circuit 156.

ACTION TAKEN WHEN THE DTC SETS
^ The BCM stores DTC B2453 in memory.
^ The BCM turns off its output to circuit 156.

CONDITIONS FOR CLEARING THE DTC
^ A short to B+ is no longer detected by the BCM in circuit 156 when the ignition switch is turned from the LOCK or OFF position to the RUN position.
^ 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 B+ in circuit 156.
- The BCM is shorted to B+ internally.
^ 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 reappear.
^ DTC P1626 will set in the Powertrain Control Module (PCM) when the ignition switch is in the RUN position with the BCM disconnected. When BCM diagnostics and repairs are completed, refer to the Engine Controls for additional information on PCM related DTCs. Powertrain Management

TEST DESCRIPTION
Numbers below refer to the step numbers on the diagnostic table.
3. Checks for a short to B+ in circuit 156.
4. Determines whether the malfunction is intermittent or the BCM is faulty.