GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Seville 🢒 Body and Accessories 🢒 Seats 🢒 Lumbar Support Does Not Move Up or Down

Lumbar Support Does Not Move Up or Down AL2

Step

Action

Value(s)

Yes

No

1

Was the entire Lumbar Support System Check performed?

--

Go to Step 2

Go to Lumbar Support System Check

2
  1. Backprobe the lumbar switch connector with a DMM from cavity B (TAN) (LH) or cavity C (PNK) (RH) to ground.
  2. Move the lumbar switch UP.

Is the voltage within the specified range?

10-15 V

Go to Step 3

Go to Step 4

3
  1. Backprobe the lumbar switch connector with a DMM from cavity C (PPL) (LH) or cavity B (ORN) (RH) to ground.
  2. Move the lumbar switch DOWN.

Is the voltage within the specified range?

10-15 V

Go to Step 5

Go to Step 4

4

Replace the lumbar switch. Refer to Lumbar Switch Replacement .

Is the lumbar switch replacement complete?

--

Go to Lumbar Support System Check

--

5
  1. Backprobe the lumbar up/down motor connector with a DMM from cavity A (PNK) (LH) or (TAN/WHT) (RH) to ground.
  2. Move the lumbar switch UP.

Is the voltage within the specified range?

10-15 V

Go to Step 6

Go to Step 8

6
  1. Backprobe the lumbar up/down motor connector with a DMM from cavity B (ORN) (LH) or (PPL/WHT) (RH) to ground.
  2. Move the lumbar switch DOWN.

Is the voltage within the specified range?

10-15 V

Go to Step 7

Go to Step 9

7

Replace the lumbar up/down motor. Refer to Lumbar Component Replacement - Power .

Is the lumbar up/down motor replacement complete?

--

Go to Lumbar Support System Check

--

8

Repair the open in CKT 768 (TAN) or (PNK) (LH) or CKT 793 (PNK) or (TAN/WHT) (RH). Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Lumbar Support System Check

--

9

Repair the open in CKT 767 (PPL) or (ORN) (LH) or CKT 792 (ORN) or (PPL/WHT) (RH). Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Lumbar Support System Check

--

Lumbar Support Does Not Move Up or Down A45

Step

Action

Value(s)

Yes

No

1

Was the entire Lumbar Support System Check performed?

--

Go to Step 2

Go to Lumbar Support System Check

2
  1. Turn the ignition switch the ON position.
  2. Connect a scan tool to the data link connector (DLC).
  3. Select INPUTS from the memory seat module (MSM) DATA LIST.
  4. Move 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.

Does 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. Connect a DMM from the LH lumbar up/down motor cavity A (TAN) to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 5

Go to Step 13

5

Connect a DMM from the lumbar up/down motor cavity B (PPL) to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 8

Go to Step 14

6
  1. Disconnect the memory seat module (MSM) connector C2.
  2. Connect a DMM from the MSM connector C2 cavity C11 (WHT) to ground.
  3. Move the lumbar switch UP.

Is the voltage within the specified range?

10-15 V

Go to Step 7

Go to Step 9

7
  1. Connect a DMM from the MSM connector C2 cavity C12 (YEL/BLK) to ground.
  2. Move the lumbar switch DOWN.

Is the voltage within 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 .

Is the MSM replacement complete?

--

Go to Lumbar Support System Check

--

9
  1. Disconnect the LH lumbar switch connector.
  2. Connect a DMM from the MSM connector C2 cavity C11 (WHT) to the LH lumbar switch connector cavity B (WHT).

Is the resistance less than the specified value?

5 ohms

Go to Step 11

Go to Step 15

10

Connect a DMM from the MSM connector C2 cavity C12 (YEL/BLK) to the LH lumbar switch connector cavity C (YEL/BLK).

Is the resistance less than the specified value?

5 ohms

Go to Step 11

Go to Step 16

11

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

Is the LH lumbar switch replacement complete?

--

Go to Lumbar Support System Check

--

12

Replace the LH lumbar up/down motor. Refer to Lumbar Component Replacement - Power .

Is the LH lumbar up/down motor replacement complete?

--

Go to Lumbar Support System Check

--

13

Repair the open in CKT 768 (PNK) or (TAN) between the MSM and the LH lumbar up/down motor. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Lumbar Support System Check

--

14

Repair the open in CKT 767 (ORN) or (PPL) between the MSM and the LH lumbar up/down motor. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Lumbar Support System Check

--

15

Repair the open in CKT 1066 (WHT) between the LH lumbar switch and the MSM. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Lumbar Support System Check

--

16

Repair the open in CKT 1067 (YEL/BLK) between the LH lumbar switch and the MSM. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Lumbar Support System Check

--