GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 Park Avenue 🢒 Body and Accessories 🢒 Seats 🢒 Lumbar Support Does Not Move In or Out

Lumbar Support Does Not Move In or Out w/o A45

Step

Action

Value(s)

Yes

No

1

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

--

Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2
  1. Measure the voltage from the Lumbar IN control circuit of the lumbar switch to a good ground.
  2. Activate the lumbar switch IN.

Does the voltage measure within the specified range?

10-15 V

Go to Step 3

Go to Step 4

3
  1. Measure the voltage from the Lumbar OUT control circuit of the lumbar switch to a good ground.
  2. Activate the lumbar switch OUT.

Does the voltage measure within the specified range?

10-15 V

Go to Step 6

Go to Step 4

4

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 12

Go to Step 5

5

Replace the lumbar switch. Refer to Lumbar Switch Replacement .

Did you complete the replacement?

--

Go to Step 12

--

6
  1. Measure the voltage from the Lumbar IN control circuit of the lumbar motor to a good ground.
  2. Activate the lumbar switch IN.

Does the voltage measure within the specified range?

10-15 V

Go to Step 7

Go to Step 10

7
  1. Measure the voltage from the Lumbar OUT control circuit of the lumbar motor to a good ground.
  2. Activate the lumbar switch OUT.

Does the voltage measure within the specified range?

10-15 V

Go to Step 8

Go to Step 11

8

Inspect for poor connections at the harness connector of the lumbar horizontal 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 9

9

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

Did you complete the replacement?

--

Go to Step 12

--

10

Repair the open in the Lumbar IN control circuit between the lumbar switch and the lumbar horizontal motor. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 12

--

11

Repair the open in the Lumbar OUT control circuit between the lumbar switch and the lumbar horizontal motor. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

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 In or Out w/ A45

Step

Action

Value(s)

Yes

No

1

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

--

Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2
  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, observe the Lumbar Switches parameter in the Memory Seat Module data list.
  3. Activate the lumbar switch Forward and backward.

Does the scan tool indicate that the lumbar switch moves Forward and backward?

--

Go to Step 3

Go to Step 6

3
  1. Disconnect the lumbar horizontal motor.
  2. Connect a fused jumper from battery positive voltage (B+) to one lumbar horizontal motor terminal.
  3. Connect a fused jumper from the other Lumbar horizontal motor terminal to ground.

Did the motor run?

--

Go to Step 4

Go to Step 14

4
  1. Disconnect the memory seat module (MSM) connector C1.
  2. Disconnect the memory seat module (MSM) connector C2.
  3. Measure the resistance from the Lumbar IN motor cavity to ground.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 5

Go to Step 16

5

Measure the resistance from the Lumbar OUT motor cavity to ground.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 8

Go to Step 16

6
  1. Disconnect the memory seat module (MSM) connector C2.
  2. Measure the voltage from the Lumbar IN control circuit of the memory seat module (MSM) to ground.
  3. Activate the lumbar switch IN.

Does the voltage measure less than the specified range?

10-15 V

Go to Step 7

Go to Step 10

7
  1. Measure the voltage from the Lumbar OUT control circuit of the memory seat module (MSM) to ground.
  2. Activate the lumbar switch OUT.

Does the voltage measure less than the specified range?

10-15 V

Go to Step 8

Go to Step 11

8

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 in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 18

Go to Step 9

9

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

Did you complete the replacement?

--

Go to Step 18

--

10
  1. Disconnect the lumbar switch connector.
  2. Measure the resistance of the Lumbar IN control circuit between the lumbar switch and the memory seat module (MSM).

Does the resistance measure less than the specified range?

5 ohms

Go to Step 12

Go to Step 17

11

Measure the resistance of the Lumbar OUT control circuit between the lumbar switch and the memory seat module (MSM).

Does the resistance measure less than the specified range?

5 ohms

Go to Step 12

Go to Step 17

12

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 13

13

Replace the lumbar switch. Refer to Lumbar Switch Replacement .

Did you complete the replacement?

--

Go to Step 18

--

14

Inspect for poor connections at the harness connector of the lumbar horizontal 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 15

15

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

Did you complete the replacement?

--

Go to Step 18

--

16

Repair the open in the appropriate circuit between the memory seat module (MSM) and the lumbar horizontal motor. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 18

--

17

Repair the open in the appropriate circuit between the lumbar switch and the memory seat module (MSM). Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

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