B3127

CIRCUIT DESCRIPTION
The body control module (BCM) controls the driver door lock actuator. The ground is applied to the door lock actuator lock control circuit through the door lock portion of the door lock/unlock relay. When the body control module applies power to the driver door lock actuator unlock control circuit, the door lock actuator energizes and unlocks the door lock.

CONDITIONS FOR RUNNING THE DTC
The BCM must be commanding the driver door lock actuator to unlock the door lock. The battery positive voltage supplied to the BCM is within normal operating range of 9-16 volts.

CONDITIONS FOR SETTING THE DTC
^ The BCM detects a short to ground in the driver door lock actuator unlock control circuit or the RFA BATT fuse is open while commanding the driver door lock actuator to unlock the door lock.
^ The conditions above must be present for more than 0.3 seconds.

ACTION TAKEN WHEN THE DTC SETS
The BCM stores DTC B3127 in memory.

CONDITIONS FOR CLEARING THE DTC
^ A short to ground in the driver door lock actuator unlock control circuit is no longer detected by the BCM when the BCM is commanding the driver door lock actuator to unlock the door lock.
^ A history DTC B3127 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ A scan tool may be used to clear the DTC.

DIAGNOSTIC AIDS
^ If the DTC B3127 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.
^ The following conditions may cause an intermittent malfunction to occur:
- An intermittent short to ground in the driver door lock actuator unlock control circuit
- The driver door lock actuator is shorted to ground internally.
- The BCM is shorted to ground internally.

If the DTC B3127 is accompanied by DTC B3267, the fault may be an open or shorted battery positive voltage circuit, or an open RFA BATT fuse. Refer to Circuit Testing in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-3 Part 1:

Steps 4-13 Part 2:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible noise when the left front door lock actuator is commanded to unlock. Command the door lock actuator to lock and unlock. Repeat the commands as necessary.
3. Verifies that the BCM is providing voltage to the driver door lock actuator.
4. Tests for an open in the door lock actuator lock circuit to the driver door lock actuator.
5. Tests if voltage is constantly being applied to the driver door lock actuator.