GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 LeSabre 🢒 Body and Accessories 🢒 Doors 🢒 Power Door Locks Inoperative

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step determines if there is a rear door lock actuator control circuit shorted to ground, a condition which could open the RRDR MDL fuse located in the rear fuse block and set DTCs U1162 and U1163 simultaneously current when the rear door lock actuator is actuated.

    2.

  2. Turning ON the headlamps in this step eliminates the possibility of the inoperative door lock switch finding an alternative path to ground through the switch illumination circuit, a condition which could result in the scan tool displaying incorrect lock switch states.

    3.

  3. This step begins to determine if the lock switch or lock switch circuits are the cause of the malfunction. If the 3-amp jumper wire fuse opens when the jumper wire is connected, test the appropriate lock switch signal circuits for a short to battery voltage.

    4.

  4. This step determines if the door lock actuator unlock circuit may be the cause of the malfunction. If the test lamp is already illuminated before operating the lock switch to Unlock, test the door lock actuator unlock circuit for a short to battery voltage.

    5.

  5. This step determines if the door lock actuator lock circuit may be the cause of the malfunction. If the test lamp is already illuminated before operating the lock switch to Lock, test the door lock actuator lock circuit for a short to battery voltage.

    6.

  6. This step directs you to, either inspect for poor connections at the passenger door module , or, at the driver door switch assembly as a pre-requisite to replacing the passenger door module or driver door switch assembly. This is because lock switch signals for the driver door are detected and processed by the driver door switch assembly, while lock switch signals for the passenger door are detected and processed by the passenger door module.

    7.

  7. This step directs you to, either replace the passenger door module or driver door switch assembly. This is because lock switch signals for the driver door are detected and processed by the driver door switch assembly, while lock switch signals for the passenger door are detected and processed by the passenger door module.

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

DEFINITION: This test assumes that all DTCs have been diagnosed.

1

Did you perform the Door Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Door Systems

2

Verify that the Power Door Locks Inoperative complaint is present.

Does the power door lock system operate as described in the Description and Operation?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Install a scan tool.
  2. Close all of the vehicles doors.
  3. Turn ON the ignition, with the engine OFF.
  4. Operate both of the door lock switches to both the lock and unlock positions.

Did DTCs U1162 and U1163 set current when you operated either one of the lock switches?

Go to Step 14

Go to Step 4

4

  1. Turn ON the headlamps switch.
  2. With the scan tool, observe both door lock switches parameters in the Driver Door Module, Inputs list.
  3. Operate both of the door lock switches to both the lock and unlock positions.

Did the parameter change to both the Lock and Unlock states for both switches?

Go to Step 7

Go to Step 5

5

Important: If the 3-amp fuse of the jumper wire opens when the jumper wire is connected, test the appropriate signal circuit for a short to battery positive voltage.

  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the inoperative door lock switch.
  3. Connect a 3-amp fused jumper wire between the lock signal circuit of the harness connector and ground.
  4. Turn ON the ignition, with the engine OFF.
  5. With the scan tool, observe the appropriate door lock switch parameter.
  6. Turn OFF the ignition.
  7. Connect the 3-amp fused jumper wire between the unlock signal circuit of the harness connector and a good ground.
  8. Turn ON the ignition, with the engine OFF.
  9. With the scan tool, observe the appropriate door lock switch parameter.

Did the parameter change state to both the Lock and Unlock states as expected?

Go to Step 6

Go to Step 10

6
  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the lock signal circuit and the ground circuit of the harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the appropriate Door Lock Switch parameter.

Did the parameter change state to Lock as expected?

Go to Step 15

Go to Step 19

7

Important: If the test lamp is already illuminated before operating the door lock switch to UNLOCK, test the door lock actuator unlock circuit for a short to battery positive voltage.

  1. Disconnect the harness connector of the inoperative door lock actuator.
  2. Connect a test lamp between the door lock actuator unlock circuit of the harness connector and a good ground.
  3. Operate either one of the door lock switches to UNLOCK.

Does the test lamp flash once upon operating the lock switch to UNLOCK?

Go to Step 8

Go to Step 11

8

Important: If the test lamp is already illuminated before operating the door lock switch to LOCK, test the door lock actuator lock circuit for a short to battery positive voltage.

  1. Connect a test lamp between the door lock actuator lock circuit of the harness connector and a good ground.
  2. Operate either one of the door lock switches to LOCK.

Does the test lamp flash once upon operating the lock switch to LOCK?

Go to Step 9

Go to Step 11

9
  1. Connect a test lamp between the door lock actuator unlock circuit and the door lock actuator lock circuit of the harness connector.
  2. Operate either one of the door lock switches to both LOCK and UNLOCK.

Does the test lamp flash once upon operating the lock switch to LOCK and once upon operating the lock switch to UNLOCK?

Go to Step 18

Go to Step 13

10

Important: If a door lock switch signal circuit is found to be shorted to battery positive voltage, the door lock switch may need to be replaced also.

Test the appropriate door lock switch signal and ground circuits for shorts to each other, a short to battery positive voltage, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 16

11

Test the door lock actuator control circuits for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 12

12

Test the door lock actuator control circuits for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 17

13

Test the inoperative door module logic ground circuit of the C1 connector for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 17

14

Test the door lock actuator control circuits of both rear doors for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 23

15

Inspect for poor connections at the inoperative door lock switch harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 20

16

Inspect for poor connections at the harness connector of the appropriate passenger door module, or, if the inoperative lock is the driver door lock, at the harness connector of the driver door switch assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 21

17

Inspect for poor connections at the harness connector of the inoperative door module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 22

18

Inspect for poor connection at the harness connector of the inoperative door lock actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 23

19

Repair the open in the inoperative door lock switch ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 24

--

20

Replace the inoperative door lock switch. Refer to Door Lock Switch Replacement .

Did you complete the replacement?

Go to Step 24

--

21

Replace the inoperative passenger door module, or, if the inoperative lock is the driver door lock, replace the driver door switch assembly. Refer to Door Control Module Replacement or Front Door Switch Replacement .

Did you complete the replacement?

Go to Step 24

--

22

Replace the inoperative door module. Refer to Door Control Module Replacement .

Did you complete the replacement?

Go to Step 24

--

23

Replace the inoperative door lock actuator. Refer to Front Side Door Latch Replacement or Rear Side Door Latch Replacement .

Did you complete the replacement?

Go to Step 24

--

24

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2