GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2006 🢒 Terraza Ext. 🢒 Body 🢒 Doors 🢒 Power Door Locks Inoperative - Passenger Door

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

BCM B+

1,2

1,2

1,2

--

Driver Door Lock Switch Lock Signal

3

3

3

--

Driver Door Lock Switch Unlock Signal

3

3

3

--

Passenger Door Lock Switch Lock Signal

3

3

3

--

Passenger Door Lock Switch Unlock Signal

3

3

3

--

Driver Door Lock Actuator Unlock Control

1,2

1,2

1,2

--

Door Lock Actuator Unlock Control

1,2

1,2

1,2

--

Door Lock Actuator Lock Control

1,2

1,2

1,2

--

Door Lock Switch Ground

--

3

3

--

1. Front Door/Liftgate Lock Malfunction

2. Sliding Door Lock Malfunction

3. Door Lock Switch Malfunction

Circuit/System Description

The passenger doors include the passenger front door, the passenger rear sliding doors, and the liftgate door. When the body control module (BCM) detects a transition of either of the door lock switches to the unlock position, it switches the door lock actuator unlock control circuits to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the passenger door lock actuator motors transition to the unlock position.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Power Door Systems Connector End Views

Description and Operation

Power Door Locks Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Verification
  1. Ignition ON, observe the scan tool RF Door Lock Switch and RF Door Unlock Switch parameters while using the passenger door lock switch. The parameter should change from Active to Inactive.
    2. ⇒If the value does not change, refer to Passenger Door Lock Switch Malfunction.
  2. Command the Lock All Doors and Unlock All Doors with a scan tool. The passenger door should perform the UNLOCK and LOCK functions.
    3. ⇒If the passenger door does not UNLOCK or LOCK, refer to Passenger Door Lock Malfunction.

Circuit/System Testing

Passenger Door Lock Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the passenger door lock switch.
  2. Test for less than 1.0 ohm between the ground circuit terminal C and ground.
    3. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool RF Door Lock Switch parameter is Inactive.
    4. ⇒If not the specified value, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the BCM.
  4. Verify the scan tool RF Door Unlock Switch parameter is Inactive.
    5. ⇒If not the specified value, test the signal circuit terminal E for a short to ground. If the circuit tests normal, replace the BCM.
  5. Install a 3A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool RF Door Unlock Switch parameter is Active.
    6. ⇒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.
  6. Install a 3A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool RF Door Lock Switch parameter is Active.
    7. ⇒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.
  7. If all circuits test normal, test or replace the passenger door lock switch.

Passenger Door Lock Malfunction

  1. Ignition OFF, disconnect the harness connector at the passenger door latch assembly.
  2. Test for less than 1.0 ohm between the control circuit terminal B and ground.
    3. ⇒If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.
  3. Test for less than 1.0 ohm between the control circuit terminal A and ground.
    4. ⇒If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.
  4. Connect a test lamp between the control circuit terminal B and control circuit terminal A.
  5. Ignition ON, command the passenger door latch assembly to LOCK and UNLOCK by using the passenger door lock switch. The test lamp should illuminate when commanding the LOCK and UNLOCK states.
    6. ⇒If the test lamp remains OFF during either of the commands, test for a short to ground or an open/high resistance on either control circuit. If the circuits test normal, replace the BCM.
  6. If all circuits test normal, test or replace the passenger door latch assembly.

Component Testing

Door Lock Switch

  1. Ignition OFF, disconnect the harness connector at the passenger door lock switch.
  2. Test for infinite resistance between the signal terminal E and the ground terminal C with the switch in the open position.
    3. ⇒If not the specified value, replace the passenger door lock switch.
  3. Test for infinite resistance between the signal terminal D and the ground terminal C with the switch in the open position.
    4. ⇒If not the specified value, replace the passenger door lock switch.
  4. Test for less than 2.0 ohms between the signal terminal E and the ground terminal C with the switch in the Unlock position.
    5. ⇒If greater than the specified range, replace the passenger door lock switch.
  5. Test for less than 2.0 ohms between the signal terminal D and the ground terminal C with the switch in the Lock position.
    6. ⇒If greater than the specified range, replace the passenger door lock switch.

Driver Door Latch

  1. Ignition OFF, disconnect the harness connector at the passenger door latch assembly.
  2. Install a 15A fused jumper wire between one of the control terminals and 12V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the driver door latch assembly should perform the LOCK/UNLOCK functions.
    3. ⇒If it does not perform as specified, replace the passenger door latch assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Door Lock Switch Replacement - Passenger Front
    •  Front Side Door Lock Replacement
    •  Control Module References for BCM replacement, setup and programming.