GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

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

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Driver Door Latch Control

1

1

B2517

--

Driver Door Latch Enable Control

1

1

B2517

--

Front Passenger Door Latch Control

1

1

B2518

--

Front Passenger Door Latch Enable Control

1

1

B2518

--

Driver Door Lock Switch Lock Signal

B3152

2

2

--

Driver Door Lock Switch Unlock Signal

B3142

2

2

--

Left Front Exterior Door Handle Switch Signal

B3849

1

1

--

Left Front Interior Door Handle Switch Signal

B3848

1

1

--

Passenger Door Lock Switch Lock Signal

B3155

2

2

--

Passenger Door Lock Switch Unlock Signal

B3145

2

2

--

Right Front Exterior Door Handle Switch Signal

B1474

1

1

--

Right Front Interior Door Handle Switch Signal

B2981

1

1

--

Driver Exterior Door Handle Switch Ground

--

1

1

--

Driver Interior Door Handle Switch Ground

--

1

1

--

Passenger Exterior Door Handle Switch Ground

--

1

1

--

Passenger Interior Door Handle Switch Ground

--

1

1

--

Driver Door Lock Switch Ground

--

2

2

--

Passenger Door Lock Switch Ground

--

2

2

--

  1. Power Door Latch System Malfunction
  2. Power Door Locks Inoperative

Circuit/System Description

When the remote control door lock receiver (RCDLR) receives an input from either the driver exterior door handle switch or driver interior door handle switch, it checks the Lock/Unlock status of the driver door. If the status of the driver door is Unlock, the RCDLR applies the ground for the driver power door latch.

At the same time that the RCDLR is receiving its input, the driver door module (DDM) is also receiving the same input. When the DDM receives its input from the door handle switch, it checks the window indexing status of the driver door. If the window is below the index point, it sends a serial data message to the body control module (BCM) to apply voltage for the driver power door latch. If the window is above the index point, it will first index the window, then send a serial data message to the BCM to apply voltage for the driver power door latch.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Latch Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Door Latch Inoperative from Exterior Door Handle Switch

  1. Ignition OFF, disconnect the harness connector at the appropriate exterior door handle switch.
  2. Verify that a test lamp illuminates between B+ and the ground circuit terminal C.
  3. If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Exterior Door Handle switch parameter is Inactive.
  5. If not the specified value, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the adoor control module.
  6. Verify the RCDLR scan tool Exterior Door Handle switch parameter is Inactive.
  7. If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the RCDLR.
  8. Install a 3A fused jumper wire between the signal circuit terminal D and ground terminal C. Verify the scan tool Exterior Door Handle switch parameter is Active.
  9. 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 appropriate door control module.
  10. Install a 3A fused jumper wire between the signal circuit terminal A and ground terminal C. Verify the RCDLR scan tool Exterior Door Handle Switch parameter is Active.
  11. 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 RCDLR.
  12. If all circuits test normal, test or replace the exterior door handle switch.

Door Latch Inoperative from Interior Door Handle Switch

  1. Ignition OFF, disconnect the harness connector at the appropriate interior door handle switch.
  2. Verify that a test lamp illuminates between B+ and the ground circuit terminal A.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Interior Door Handle Switch parameter is Inactive.
  5. If not the specified value, test the signal circuit terminal C for a short to ground. If the circuit tests normal, replace the appropriate door control module.
  6. Verify the RCDLR scan tool Interior Door Handle Switch parameter is Inactive.
  7. If not the specified value, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the RCDLR.
  8. Install a 3A fused jumper wire between the signal circuit terminal C and ground terminal A. Verify the scan tool Interior Door Handle Switch parameter is Active.
  9. 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 door control module.
  10. Install a 3A fused jumper wire between the signal circuit terminal B and ground terminal A. Verify the RCDLR scan tool Interior Door Handle Switch parameter is Active.
  11. 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 RCDLR.
  12. If all circuits test normal, test or replace the interior door handle switch.

Door Latch Inoperative from All Door Handle Switches

  1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
  2. Connect a test lamp between the control circuit terminal listed below and ground.
  3. • Driver door latch control circuit terminal 3
    • Passenger door latch control circuit terminal 8
  4. Ignition ON, command the door latch by using the interior door handle switch. The test lamp should turn ON when activating the door handle switch.
  5. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
    If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
  6. Connect a test lamp between the control circuit terminals listed below.
  7. • Driver door latch control circuit terminal 3 and latch enable control circuit terminal 4
    • Passenger door latch control circuit terminal 8 and latch enable control circuit terminal 9
  8. Ignition ON, command the door latch by using the interior door handle switch. The test lamp should turn ON when activating the door handle switch.
  9. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the RCDLR.
    If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the RCDLR.
  10. If all circuits test normal, test or replace the door latch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Door Lock Replacement
    •  Door Outside Handle Replacement
    •  Control Module References for BCM, DDM, DDSA or PDM replacement, setup, and programming