GM Service Manual Online
For 1990-2009 cars only

Power Seat Inoperative w/o A45

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics or Passenger Seat Schematics

Connector End View Reference: Power Seat Connector End Views

DEFINITION: One or more of the power seat functions are inoperative.

1

Did you review the power seat system description and operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Seats

2

  1. Verify that the power seat inoperative complaint is present.
  2. Attempt to operate all of the power seat motors through their full range of adjustment.

Does the power seat system operate as described in the system description and operation?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Are all of the power seat motors inoperative?

Go to Step 4

Go to Step 6

4

  1. Disconnect the seat adjuster switch.
  2. Connect a test lamp from the battery positive voltage circuit of the switch connector to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 10

5

Connect a test lamp from the battery positive voltage circuit of the switch connector to the ground circuit of the switch connector.

Does the test light illuminate?

Go to Step 9

Go to Step 11

6

  1. Disconnect the inoperative seat motor.
  2. Connect a test lamp between the motor control circuits of the harness connector.
  3. Operate the suspect seat switch in both directions.

Does the test light illuminate in both directions?

Go to Step 8

Go to Step 7

7

Test the motor control circuits for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs or Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 9

8

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

Did you find and correct the condition?

Go to Step 14

Go to Step 13

9

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

Did you find and correct the condition?

Go to Step 14

Go to Step 12

10

Repair the short to ground or open in the battery positive voltage circuit of the seat adjuster switch. Refer to Wiring Repairs or Connector Repairs .

Is the trouble corrected?

Go to Step 14

--

11

Repair the open in the ground circuit of the seat adjuster switch. Refer to Wiring Repairs or Connector Repairs .

Did you complete the repair?

Go to Step 14

--

12

Replace the seat adjuster switch . Refer to Front Seat Adjuster Replacement .

Have you finished the replacement?

Go to Step 14

--

13

Replace the seat motor. Refer to Front Seat Adjuster Replacement .

Have you finished the replacement?

Go to Step 14

--

14

Operate the system to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

Power Seat Inoperative with A45

Diagnostic Aids

The memory seat module (MSM) is also referenced as the driver position module (DPM) for this vehicle.

Test Description

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

  1. This step tests the integrity of the signal circuits of the seat adjuster switch. If the fuse in the jumper wire opens when you perform this test, a short to ground may have occurred.

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics

Connector End View Reference: Power Seat Connector End Views

DEFINITION: One or more of the power seat functions are inoperative.

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Verify that the power seat inoperative complaint is present.
  2. Attempt to operate all of the power seat motors through their full range of adjustment.

Does the power seat system operate as described in the system description and operation?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Are all of the power seat motors inoperative?

Go to Step 4

Go to Step 8

4

Probe the battery positive voltage circuit of the memory seat module connector C1 Pin-B with a test lamp that is connected to a good ground.

Does the test light illuminate?

Go to Step 5

Go to Step 16

5

Connect the test lamp between the battery positive voltage circuit and the ground circuit of the memory seat module connector C1.

Does the test lamp illuminate?

Go to Step 6

Go to Step 17

6

Probe the battery positive voltage circuit of the seat adjuster switch with a test lamp that is connected to a good ground.

Does the test light illuminate?

Go to Step 7

Go to Step 18

7

  1. Probe any one of the seat switch signal circuits of the seat adjuster switch with a test lamp that is connected to a good ground.
  2. Operate the appropriate seat switch.

Does the test light illuminate?

Go to Step 15

Go to Step 14

8

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the inoperative seat switch parameters in the Driver Position Module data list.
  4. Operate the suspect seat switch in both directions.

Does the seat switch parameters change state in both directions?

Go to Step 10

Go to Step 9

9

  1. Disconnect the seat adjuster switch.
  2. Connect a 3-amp fused jumper wire between the battery voltage circuit of the harness connector and the suspect switch signal circuit of the harness connector.
  3. With a scan tool, observe the appropriate seat switch parameter.

Does the seat parameter change state?

Go to Step 14

Go to Step 11

10

  1. Disconnect the inoperative seat motor.
  2. Connect a test lamp between the motor control circuits of the harness connector.
  3. Operate the suspect seat switch in both directions.

Does the test light illuminate in both directions?

Go to Step 13

Go to Step 12

11

Test the suspect switch signal circuit between the seat adjuster switch and the memory seat module for an open. Refer to Circuit Testing and Wiring Repairs or Connector Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 15

12

Test the motor control circuits between the memory seat module and the inoperative seat motor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs or Connector Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 15

13

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

Did you find and correct the condition?

Go to Step 22

Go to Step 20

14

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

Did you find and correct the condition?

Go to Step 22

Go to Step 19

15

Inspect for poor connections at the harness connector of the memory seat module (MSM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 21

16

Repair the short to ground or open in the battery positive circuit of the memory seat module. Refer to Wiring Repairs or Connector Repairs .

Did you find and correct the condition?

Go to Step 22

--

17

Repair the open in the ground circuit of the memory seat module. Refer to Wiring Repairs or Connector Repairs .

Did you find and correct the condition?

Go to Step 22

--

18

Repair the open in the battery positive voltage circuit of the seat adjuster switch. Refer to Wiring Repairs or Connector Repairs .

Did you find and correct the condition?

Go to Step 22

--

19

Replace the seat adjuster switch. Refer to Front Seat Adjuster Replacement .

Have you finished the replacement?

Go to Step 22

--

20

Replace the inoperative seat motor. Refer to Front Seat Adjuster Replacement .

Have you finished the replacement?

Go to Step 22

--

21

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

Have you finished the replacement?

Go to Step 22

--

22

Operate the system to verify the repair.

Did you correct the condition?

System OK

Go to Step 2