GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 LeSabre 🢒 Body and Accessories 🢒 Seats 🢒 Lumbar Support Does Not Move Up or Down

Lumbar Support Does Not Move Up or Down LH 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 UP and DOWN sensor parameter in the Memory Seat Module data list.
  3. Activate the lumbar switch UP and DOWN.

Does the scan tool indicate that the lumbar switch moves UP and DOWN?

--

Go to Step 3

Go to Step 6

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

Did the motor run?

--

Go to Step 4

Go to Step 12

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 LH lumbar UP motor cavity to ground.

Does the resistance Measure less than the specified value?

5 ohms

Go to Step 5

Go to Step 13

5

Measure the resistance from the lumbar DOWN motor cavity to ground.

Does the resistance Measure less than the specified value?

5 ohms

Go to Step 8

Go to Step 13

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

Does the voltage measure less than the specified range?

10-15 V

Go to Step 7

Go to Step 9

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

Does the voltage measure less than the specified range?

10-15 V

Go to Step 8

Go to Step 10

8

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

Did you complete the replacement?

--

Go to Step 15

--

9
  1. Disconnect the LH lumbar switch connector.
  2. Measure the resistance of the Lumbar UP control circuit between the LH lumbar switch and the memory seat module (MSM).

Does the resistance measure less than the specified range?

5 ohms

Go to Step 11

Go to Step 14

10

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

Does the resistance measure less than the specified range?

5 ohms

Go to Step 11

Go to Step 14

11

Replace the LH lumbar switch. Refer to Lumbar Switch Replacement .

Did you complete the replacement?

--

Go to Step 15

--

12

Replace the LH lumbar up/down motor. Refer to Front Seat Lumbar Support Replacement .

Did you complete the replacement?

--

Go to Step 15

--

13

Repair the open in the appropriate circuit between the MSM and the LH lumbar up/down motor. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

14

Repair the open in the appropriate circuit between the LH lumbar switch and the MSM. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2