GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 CTS 🢒 Safety and Security 🢒 Theft Deterrent 🢒 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 lock actuator control circuit of one of the rear doors shorted to ground. This condition could open the RRDR MDL fuse located in the rear fuse block and simultaneously set DTCs U1162 and U1163 when the rear door lock actuator is actuated.

    2.

  2. This step checks to see that the door module associated with the inoperative door lock recognizes the switch inputs. Turning ON the headlamps switch in this step eliminates the possibility of the inoperative door lock switch finding an alternative path to ground through the switch illumination circuit, which could result in the scan tool displaying incorrect lock switch states.

    3.

  3. This step determines 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 switch signal circuits for a short to battery positive voltage.

    4.

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

    5.

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

    6.

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

    7.

  7. This step directs you to replace either, the front 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 (DDSA), while lock switch signals for the front passenger door are detected and processed by the front passenger door module.

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

Connector End View Reference: Vehicle Access Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

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

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 one of the door lock switches to both the Lock and Unlock positions.

Did DTCs U1162 and U1163 simultaneously set current when you operated the lock switch?

Go to Step 14

Go to Step 4

4

  1. Turn ON the headlamps switch.
  2. With the scan tool, observe the Door Lock Switch parameter in the Driver Door Switch, Inputs list.
  3. Operate the driver door lock switch to both the Lock and Unlock positions.
  4. With the scan tool, observe the Door Lock Switch parameter in the front Passenger Door Module (FPDM), Inputs list.
  5. Operate the front passenger door lock switch to both the Lock and Unlock positions.

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

Go to Step 7

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the inoperative door lock switch harness connector.
  3. Connect a 3-amp fused jumper wire between the lock signal circuit of the harness connector and a good 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 the 3-amp fused jumper wire between the lock signal circuit and the ground circuit of the door lock switch 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

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

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

Go to Step 8

Go to Step 11

8

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

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

Go to Step 9

Go to Step 11

9
  1. Connect a test lamp between the Unlock circuit and the Lock circuit of the harness connector.
  2. Operate either one of the front door lock switches to both Lock and Unlock.

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

Go to Step 18

Go to Step 13

10

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

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

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 .

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 voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 24

Go to Step 17

13

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

Did you find and correct the condition?

Go to Step 24

Go to Step 17

14

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

Did you find and correct the condition?

Go to Step 24

Go to Step 18

15

Inspect for poor connections at the harness connector of the appropriate door lock switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 24

Go to Step 20

16

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

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 appropriate door module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 24

Go to Step 22

18

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

Did you find and correct the condition?

Go to Step 24

Go to Step 23

19

Repair the appropriate door lock switch ground circuit for an open. Refer to Wiring Repairs .

Did you find and correct the condition?

Go to Step 24

--

20

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

Did you complete the replacement?

Go to Step 24

--

21

Replace the passenger door module, or if the inoperative lock is the driver door lock, replace the DDSA. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 24

--

22

Replace the door module. Refer to Control Module References for replacement, setup, and programming.

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