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For 1990-2009 cars only

Lumbar Support Does Not Move Up or Down w/o Memory-A45

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics , Passenger Seat Schematics , or Rear Seat 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 that the Lumbar Support Does Not Move Up or Down complaint is present.

Does the lumbar support 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 lumbar motor up control circuit of the lumbar vertical motor with a test lamp that is connected to a good ground.
  2. Operate the lumbar motor UP adjuster switch.

Does the test lamp illuminate?

Go to Step  4

Go to Step 6

4

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

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5

  1. Disconnect the lumbar vertical motor harness connector.
  2. Connect a test lamp between the lumbar motor up control circuit and the lumbar motor down control circuit of the motor harness connector.
  3. Operate the lumbar 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 lumbar 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 lumbar 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 lumbar 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 lumbar 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 lumbar adjuster switch. Refer to Power Seat Switch Replacement .

Did you complete the replacement?

Go to Step 12

--

11

Replace the lumbar vertical motor. Refer to Front Seat Lumbar Support 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

Lumbar Support Does Not Move Up or Down with Memory-A45

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Verify that the Lumbar Support Does Not Move Up or Down complaint is present.

Does the lumbar support 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 Lumbar Up parameter in the Memory Seat Module (MSM) data list.
  4. Operate the lumbar UP switch.

Does the Seat Lumbar Up parameter change state?

Go to Step 4

Go to Step 6

4

  1. With a scan tool, observe the Seat Lumbar Down parameter.
  2. Operate the lumbar DOWN switch.

Does the Seat Lumbar Down parameter change state?

Go to Step 5

Go to Step 7

5

  1. Disconnect the lumbar vertical motor harness connector.
  2. Connect a test lamp between the lumbar motor up control circuit and the lumbar motor down control circuit of the harness connector.
  3. Operate the lumbar 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 lumbar switch harness connector.
  2. Connect a 3-amp fused jumper wire between the battery positive voltage circuit and the lumbar up switch signal circuit of the harness connector.
  3. With a scan tool, observe the Seat Lumbar Up parameter.

Does the Seat Lumbar Up parameter change state?

Go to Step 13

Go to Step 10

7

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

Does the Seat Lumbar Down parameter change state?

Go to Step 13

Go to Step 11

8

Test the lumbar motor up control circuit between the MSM and the lumbar 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 lumbar motor down control circuit between the MSM and the lumbar 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 lumbar up switch signal circuit between the lumbar switch and the MSM 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 lumbar down switch signal circuit between the lumbar switch and the MSM 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 MSM. 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 lumbar 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 lumbar vertical motor. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 17

15

Replace the MSM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 18

--

16

Replace the lumbar switch. Refer to Front Seat Lumbar Control Switch Replacement or Rear Seat Lumbar Control Switch Replacement .

Did you complete the replacement?

Go to Step 18

--

17

Replace the lumbar vertical motor. Refer to Front Seat Lumbar Support Replacement or Rear Seat Lumbar Support 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

Lumbar Support Does Not Move Up or Down Massaging Lumbar-AM3 w/o Memory-A45

Step

Action

Value (s)

Yes

No

Schematic Reference: Driver Seat Schematics or Passenger Seat Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you review the lumbar vertical operation and perform the necessary inspection?

--

Go to Step 2

Go to Symptoms - Seats

2

Verify that the Lumbar Support Does Not Move Up or Down complaint is present.

Does the lumbar support 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

Measure the voltage from the battery positive voltage circuit of the massage module to a good ground.

Does the voltage measure within the specified range?

9-16 V

Go to Step 4

Go to Step 19

4

Measure the voltage from the battery positive voltage circuit of the massage module to the ground circuit of the massage module.

Does the voltage measure within the specified range?

9-16 V

Go to Step 5

Go to Step 20

5

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

Does the test lamp illuminate in both directions?

--

Go to Step 17

Go to Step 6

6

  1. Connect a test lamp from the lumbar up switch signal circuit of the massage module connector to a good ground.
  2. Operate the lumbar UP switch.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 14

7

  1. Connect a test lamp from the lumbar down switch signal circuit of the massage module connector to a good ground.
  2. Operate the lumbar DOWN switch.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 15

8

  1. Disconnect the harness connector of the lumbar vertical position sensor.
  2. Operate the lumbar switch in the UP or DOWN direction in order to wake up the massage module.
  3. Measure the voltage from the 5-volt reference circuit of the sensor connector to a good ground.

Does the voltage measure within the specified range?

4.50-5.50 V

Go to Step 9

Go to Step 12

9

  1. Connect the lumbar vertical position sensor connector.
  2. Disconnect the lumbar massage module connector.
  3. Remove the lumbar vertical position sensor signal circuit terminal from the module connector.
  4. Connect the massage module connector.
  5. Operate the lumbar switch in the UP or DOWN direction in order to wake up the massage module.
  6. Measure the voltage from the terminal of the lumbar vertical position sensor signal circuit to a good ground.

Does the voltage measure within the specified range?

0.25-5.50 V

Go to Step 10

Go to Step 13

10

Test the lumbar motor up and down control circuits between the massage module and the lumbar vertical motor for a short to ground, high resistance, 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 11

11

Test the lumbar motor up and down control circuits between the massage module and the lumbar vertical motor for a short to battery 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 18

12

Test the 5-volt reference circuit of the lumbar vertical position sensor for the following conditions:

    • A short to ground
    • A short to voltage
    • 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 18

13

Test the signal circuit of the lumbar vertical position sensor for the following conditions:

    • A short to ground
    • A short to voltage
    • 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 18

14

Test the lumbar up switch signal circuit between the lumbar switch and the massage module 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 16

15

Test the lumbar down switch signal circuit between the lumbar switch and the massage module 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 16

16

Inspect for poor connections at the harness connector of the lumbar 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 24

Go to Step 21

17

Inspect for poor connections at the harness connectors of the lumbar vertical motor/position sensor 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 22

18

Inspect for poor connections at the harness connector of the lumbar massage 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 23

19

Repair the open in the battery positive voltage circuit of the lumbar massage module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 24

--

20

Repair the open in the ground circuit of the lumbar massage module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 24

--

21

Replace the lumbar switch. Refer to Front Seat Lumbar Control Switch Replacement .

Did you complete the replacement?

--

Go to Step 24

--

22

Replace the lumbar vertical motor/position sensor assembly. Refer to Front Seat Lumbar Support Replacement .

Did you complete the replacement?

--

Go to Step 24

--

23

Replace the lumbar massage module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

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

Lumbar Support Does Not Move Up or Down Massaging Lumbar-AM3 with Memory-A45

Test Description

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

  1. This step tests the integrity of the lumbar up switch. If the test lamp illuminates the switch is shorted in the active position. The switch parameter may not display active because, approximately 60 seconds after seeing the switch signal in the active state, the massage module shuts down and no longer relays the active switch signal to the memory seat module (MSM).

  2. This step tests the integrity of the lumbar down switch. If the test lamp illuminates the switch is shorted in the active position. The switch parameter may not display active because, approximately 60 seconds after seeing the switch signal in the active state, the massage module shuts down and no longer relays the active switch signal to the MSM.

  3. This step tests the integrity of the lumbar up signal circuit to the MSM. If the fuse in the jumper wire opens when you perform this test, the signal circuit is shorted to ground.

  4. This step tests the integrity of the lumbar down signal circuit to the MSM. If the fuse in the jumper wire opens when you perform this test, the signal circuit is shorted to ground.

  5. This step verifies that the massage module is receiving lumbar up motor control voltage from the MSM.

  6. This step verifies that the massage module is receiving lumbar down motor control voltage from the MSM.

  7. This step verifies the repair.

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Verify that the Lumbar Support Does Not Move Up or Down complaint is present.

Does the lumbar support 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

Operate the lumbar switch in the UP and DOWN directions.

Does the lumbar vertical motor run for approximately 1 second then stop?

Go to Step 26

Go to Step 4

4

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Seat Lumbar UP switch parameter in the Memory Seat Module (MSM) data list.
  4. Operate the lumbar switch in the UP direction.

Does the Seat Lumbar Up switch parameter change state?

Go to Step 5

Go to Step 6

5

  1. With a scan tool, observe the Seat Lumbar Down switch parameter.
  2. Operate the lumbar switch in the DOWN direction.

Does the Seat Lumbar Down switch parameter change state?

Go to Step 12

Go to Step 8

6

  1. Disconnect the massage module harness connector.
  2. Connect a test lamp from the lumbar up switch signal circuit Pin-G of the massage module connector to a good ground.

Does the test lamp illuminate?

Go to Step 22

Go to Step 7

7

With the test lamp still connected from the lumbar up switch signal circuit Pin-G of the massage module connector to a good ground, operate the lumbar switch in the UP direction.

Does the test lamp illuminate?

Go to Step 10

Go to Step 15

8

  1. Disconnect the massage module harness connector.
  2. Connect a test lamp from the lumbar down switch signal circuit Pin-H of the massage module connector to a good ground.

Does the test lamp illuminate?

Go to Step 22

Go to Step 9

9

With the test lamp still connected from the lumbar down switch signal circuit Pin-H of the massage module connector to a good ground, operate the lumbar switch in the DOWN direction.

Does the test lamp illuminate?

Go to Step 11

Go to Step 15

10

  1. Connect a 3-amp fused jumper wire between the battery positive voltage circuit of the massage module connector and the lumbar up signal circuit Pin-S of the massage module connector.
  2. With a scan tool, observe the Seat Lumbar Up switch parameter.

Does the Seat Lumbar Up switch parameter change state?

Go to Step 20

Go to Step 16

11

  1. Connect a 3-amp fused jumper wire between the battery positive voltage circuit of the massage module connector and the lumbar down signal circuit Pin-R of the massage module connector.
  2. With a scan tool, observe the Seat Lumbar Down switch parameter.

Does the Seat Lumbar Down switch parameter change state?

Go to Step 20

Go to Step 16

12

  1. Disconnect the lumbar vertical motor connector.
  2. Connect a test lamp between the motor control circuits of the lumbar motor connector.
  3. Operate the lumbar switch in the UP and DOWN directions.

Does the test lamp illuminate in both directions?

Go to Step 23

Go to Step 13

13

  1. Disconnect the massage module connector.
  2. Connect a test lamp from the lumbar motor up control circuit Pin-E of the massage module connector to a good ground.
  3. Connect a 3-amp fused jumper wire between the battery positive voltage circuit of the massage module connector and the lumbar up signal circuit Pin-S of the massage module connector.

Does the test lamp illuminate?

Go to Step 14

Go to Step 17

14

  1. Connect a test lamp from the lumbar motor down control circuit Pin-F of the massage module connector to a good ground.
  2. Connect a 3-amp fused jumper wire between the battery positive voltage circuit of the massage module connector and the lumbar down signal circuit Pin-R of the massage module connector.

Does the test lamp illuminate?

Go to Step 18

Go to Step 17

15

Test the lumbar up/down switch signal circuits between the lumbar switch and the massage module for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 22

16

Test the lumbar up/down signal circuits between the massage module and the MSM for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 25

17

Test the lumbar motor up/down control circuits between the MSM and the massage module for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 25

18

Test the lumbar motor up/down control circuits between the massage module and the lumbar vertical motor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 19

19

Test the lumbar vertical position sensor signal circuit between the sensor and the massage module for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 24

20

Test the lumbar motor up/down control circuits between the MSM and the massage module for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 21

21

Test the lumbar motor up/down control circuits between the massage module and the lumbar vertical motor for a short to battery voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 24

22

Inspect for poor connections at the harness connector of the lumbar 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 31

Go to Step 27

23

Inspect for poor connections at the harness connector of the lumbar 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 31

Go to Step 28

24

Inspect for poor connections at the harness connector of the massage module. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 29

25

Inspect for poor connections at the harness connector of the MSM. 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 31

Go to Step 30

26

Repair the open in the low reference circuit of the lumbar vertical position sensor. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 31

--

27

Replace the lumbar switch. Refer to Front Seat Lumbar Control Switch Replacement .

Did you complete the replacement?

Go to Step 31

--

28

Replace the lumbar vertical motor. Refer to Front Seat Lumbar Support Replacement .

Did you complete the replacement?

Go to Step 31

--

29

Replace the massage module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 31

--

30

Replace the MSM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 31

--

31

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2