B3808

DTC B3808

CIRCUIT DESCRIPTION
The body control module (BCM) internally grounds the door lock relay control circuit for the rear door lock relay when it receives a class 2 message from the driver door module (DDM) or passenger door module (PDM). When the BCM grounds the door lock relay control circuit the rear door lock relay is energized and locks the rear doors.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B3808 Rear Door Lock Relay Circuit

CONDITIONS FOR RUNNING THE DTC
- Battery voltage is between 9-16 volts.
- The DTC will set if the rear door lock function is active or inactive.

CONDITIONS FOR SETTING THE DTC
The DTC will set if the door lock relay control circuit is shorted to ground or open for more then one second.

ACTION TAKEN WHEN THE DTC SETS
- If a short to ground is present on the door lock relay control circuit, the door lock relay will be energized and the rear door lock actuators will be held in the lock position and will not unlock.
- If an open condition is present on the door lock relay control circuit, the rear doors will unlock but not lock.

CONDITIONS FOR CLEARING THE DTC
When the fault is no longer present, the BCM changes the current DTC to a history DTC. The BCM will clear the history DTC after 50 fault free ignition cycles.

DIAGNOSTIC AIDS
- DTC B3808 could also set if the door lock relay winding is open.
- If both DTC B3808 and B3809 are set as current, the battery positive voltage circuit or the LOCKS fuse could be open. If the LOCKS fuse is open, the cause is most likely one of the following:
- A short to ground in the relay battery positive voltage circuit.
- A short to ground in the door lock actuator lock or unlock control circuits.

TEST DESCRIPTION

Steps 1-14:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the rear door lock relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the coil side of the rear door lock relay. The LOCKS fuse supplies power to the coil side of the rear door lock relay.
4. Verifies that the body control module is providing ground to the rear door lock relay.
5. Tests if ground is constantly being applied to the rear door lock relay.