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

I/P Fuse Block B+

3

3

--

--

Driver Door Latch Control

1

1

1

--

Passenger Door Latch Control

2

2

2

--

Rear Doors Unlock Control

B3130 00

B3130 00

B3130 00

--

Rear Doors Lock Control

B3135 00

B3135 00

--

--

Driver Door Switch Ground

--

U0199 00

1

--

Passenger Door Switch Ground

--

U0200 00

2

--

I/P Fuse Block Ground

--

3

3

--

1. Driver Door Lock Malfunction

2. Passenger Door Lock Malfunction

3. Rear Door Lock Malfunction

Circuit/System Description

The driver and passenger door lock and side window switches are integrated control module switch assemblies. The DDS and PDS door lock switches are normally open, 2 position rocker type switches, with detents for lock and unlock. The DDS and PDS are directly connected to the respective door lock actuator through the door lock actuator control circuits. When a door lock or unlock function is activated from the DDS or PDS, a serial data message lock or unlock command is sent to the other door switch and body control module.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component 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

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, command the front doors to LOCK and UNLOCK by using the door lock switches, the front doors should perform LOCK and UNLOCK function.

If the driver door does not LOCK or UNLOCK, refer to Driver Door Lock Malfunction.
If the passenger door does not LOCK or UNLOCK, refer to Passenger Door Lock Malfunction.

Circuit/System Testing

Driver Door Lock Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the DDS.
  2. Test for less than 1 ohm between the ground circuit terminal 6 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp illuminates between the B+ circuit listed below and ground.
  5. • B+ circuit terminal 2
    • B+ circuit terminal 4
    If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. Ignition OFF, connect the X1 harness connector at the DDS and disconnect the harness connector at the driver door latch.
  7. Test for less than 2 ohms between the control circuit terminal 3 and ground.
  8. 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 DDS.
  9. Test for less than 2 ohms between the control circuit terminal 2 and ground.
  10. 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 DDS.
  11. Ignition ON, connect a test lamp between the control circuit terminal 3 and control circuit terminal 2.
  12. Command the door to LOCK and UNLOCK by using the driver door lock switch. The test lamp should briefly illuminate when commanding the LOCK and UNLOCK states.
  13. If the test lamp is always OFF during either of the commands, test either control circuit for a short to ground. If the circuits test normal, replace the DDS.
  14. If the circuits test normal, test or replace the driver door latch.

Passenger Door Lock Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the PDS.
  2. Test for less than 1 ohm between the ground circuit terminal 6 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp illuminates between the B+ circuit listed below and ground.
  5. • B+ circuit terminal 2
    • B+ circuit terminal 4
    If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. Ignition OFF, connect the X1 harness connector at the PDS and disconnect the harness connector at the passenger door latch.
  7. Test for less than 2 ohms between the control circuit terminal 5 and ground.
  8. 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 PDS.
  9. Test for less than 2 ohms between the control circuit terminal 6 and ground.
  10. 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 PDS.
  11. Ignition ON, connect a test lamp between the control circuit terminal 5 and control circuit terminal 6.
  12. Command the door to LOCK and UNLOCK by using the passenger door lock switch. The test lamp should briefly illuminate when commanding the LOCK and UNLOCK states.
  13. If the test lamp is always OFF during either of the commands, test either control circuit for a short to ground. If the circuits test normal, replace the PDS.
  14. If the circuits test normal, test or replace the passenger door latch.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
  2. Install a 15 amp fused jumper wire between the control terminal listed below and 12 volts:
  3. • Driver door latch control terminal 2
    • Passenger door latch control terminal 5
  4. Momentarily install a jumper wire between the control terminal listed below and ground. The door latch should perform the LOCK or UNLOCK function.
  5. • Driver door latch control terminal 3
    • Passenger door latch control terminal 6
    If the function does not perform as specified, replace the door latch.
  6. Reverse the jumper wires; the door latch should perform the UNLOCK or LOCK function.
  7. If the function does not perform as specified, replace the door latch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Front Side Door Lock Replacement
    •  Control Module References for DDS or PDS replacement, programming, and setup