B2971

DTC B2971

DIAGNOSTIC INSTRUCTIONS
- Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
- Review Strategy Based Diagnosis for an overview of the diagnostic approach.
- Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC DESCRIPTOR

DTC B2971
Driver Door Key Switch Circuit

CIRCUIT/SYSTEM DESCRIPTION
The key cylinder unlock feature will unlock all of the doors when the BCM receives a Key Unlock Switch signal for greater than 1 second and will unlock all of the doors.

CONDITIONS FOR RUNNING THE DTC
Battery voltage must be between 9-16 volts.

CONDITIONS FOR SETTING THE DTC
- The BCM detects the Key Unlock Switch Signal has a fault.
- The conditions above must be present for more than 60 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The BCM stores the DTC to memory.
- The door lock actuators will not lock or unlock.

CONDITIONS FOR CLEARING THE DTC
- This DTC will change from current to history when the fault is no longer present.
- A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
- The technician issues a scan tool CLEAR DTCs command.

CIRCUIT/SYSTEM VERIFICATION
Ignition OFF, insert the key into the drivers door lock cylinder, turn the key clockwise and hold for greater than 1 second and turn the key counterclockwise and hold for greater than 1 second. Observe the scan tool Door Lock Requestor parameters, the reading should be Door Key Cyl.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the harness connector at the Driver Door Latch Assembly.
2. Test for less than 1.0 ohm of resistance between the ground circuit terminal 8 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Drvr Door Unlock Cmd is OFF. If not the specified value, test the signal circuit terminal 9 for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3-amp fused jumper wire between the signal circuit terminal 9 and ground, verify the scan tool Drvr Door Unlock Cmd is ON.
- If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits tests normal, replace the Driver Door Latch Assembly.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
- Door Lock Cylinder Replacement
- Programming and Relearning Programming and Relearning