GM Service Manual Online
For 1990-2009 cars only

Power Seat Does Not Tilt Rearward w/o A45

Step

Action

Yes

No

Schematic Reference: Power Seats Schematics

Connector End View Reference: Power Seat Connector End Views

1

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

Go to Step 2

Go to Symptoms - Seats

2

Verify at the Power Seat Does Not Tilt Rearward complaint is present.

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

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

Go to Step 3

3

  1. Probe the rear vertical motor up control circuit of the seat rear vertical motor with a test lamp that is connected to a good ground.
  2. Operate the seat rear vertical motor UP adjuster switch.

Does the test lamp illuminate?

Go to Step 4

Go to Step 6

4

  1. Probe the rear vertical motor down control circuit of the seat rear vertical motor with a test lamp that is connected to a good ground.
  2. Operate the seat rear vertical motor DOWN adjuster switch .

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5

  1. Disconnect the seat rear vertical motor harness connector.
  2. Connect a test lamp between the rear vertical motor up control circuit and the rear vertical motor down control circuit of the motor harness connector.
  3. Operate the seat rear vertical motor adjuster switch in the UP and DOWN directions.

Does the test lamp illuminate in both directions?

Go to Step 9

Go to Step 8

6

Test the seat rear vertical motor up control circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 8

7

Test the seat rear vertical motor down control circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 8

8

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

9

Inspect for poor connections at the harness connector of the seat rear vertical motor. 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 12

Go to Step 11

10

Replace the seat adjuster switch. Refer to Power Seat Switch Replacement .

Did you complete the replacement?

Go to Step 12

--

11

Replace the seat rear vertical motor. Refer to Seat Adjuster Motor Replacement .

Did you complete the replacement?

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

Power Seat Does Not Tilt Rearward with A45

Step

Action

Yes

No

Schematic Reference: Memory Seats Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you perform the Diagnostic System Check - Power Seats Systems?

Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2

Verify that the Power Seat Does Not Tilt Rearward complaint is present.

Does the power seat system operate as described in the system 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. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Seat Rear Up parameter in the Memory Seat Module data list.
  4. Operate the power seat rear vertical UP switch.

Does the Seat Rear Up parameter change state?

Go to Step 4

Go to Step 6

4

  1. With a scan tool, observe the Seat Rear Down parameter.
  2. Operate the power seat rear vertical DOWN switch.

Does the Seat Rear Down parameter change state?

Go to Step 5

Go to Step 7

5

  1. Disconnect the seat rear vertical motor harness connector.
  2. Connect a test lamp between the seat rear vertical motor up control circuit and the seat rear vertical motor down control circuit of the harness connector.
  3. Operate the power seat rear vertical switch in the UP and DOWN directions.

Does the test lamp illuminate in both directions?

Go to Step 14

Go to Step 8

6

  1. Disconnect the seat adjuster switch harness connector.
  2. Connect a 3-amp fused jumper wire between the battery positive voltage circuit and the power seat rear vertical up switch signal circuit of the harness connector.
  3. With a scan tool, observe the Seat Rear Up parameter.

Does the Seat Rear Up parameter change state?

Go to Step 13

Go to Step 10

7

  1. Disconnect the seat adjuster switch harness connector.
  2. Connect a 3-amp fused jumper wire between the battery positive voltage circuit and the power seat rear vertical down switch signal circuit of the harness connector.
  3. With a scan tool, observe the Seat Rear Down parameter.

Does the Seat Rear Down parameter change state?

Go to Step 13

Go to Step 11

8

Test the seat rear vertical motor up control circuit between the memory seat module and the rear vertical motor 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 18

Go to Step 9

9

Test the seat rear vertical motor down control circuit between the memory seat module and the rear vertical motor 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 18

Go to Step 12

10

Test the power seat rear vertical up switch signal circuit between the seat adjuster switch and the memory seat module for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 12

11

Test the power seat rear vertical down switch signal circuit between the seat adjuster switch and the memory seat module for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 12

12

Inspect for poor connections at the harness connector of the memory seat 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 18

Go to Step 15

13

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 16

14

Inspect for poor connections at the harness connector of the seat rear vertical motor. 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 18

Go to Step 17

15

Replace the memory seat module. Refer to Memory Seat Control Module Replacement .

Did you complete the replacement?

Go to Step 18

--

16

Replace the seat adjuster switch. Refer to Power Seat Switch Replacement .

Did you complete the replacement?

Go to Step 18

--

17

Replace the seat rear vertical motor. Refer to Seat Adjuster Motor Replacement .

Did you complete the replacement?

Go to Step 18

--

18

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2