GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Blazer - 4WD - RHD 🢒 Body and Accessories 🢒 Seats 🢒 Lumbar Support Inoperative

Step

Action

Value(s)

Yes

No

1

Has the Lumbar Support System Check been performed?

--

Go to Step 2

Go to Lumbar Support System Check

2

Inspect the HTD SEAT fuse in the underhood fuse block.

Is the fuse good?

--

Go to Step 4

Go to Step 3

3

Locate and repair short to ground in CKT 2240 (ORN), CKT 610 (PNK), CKT 611 (DK BLU), CKT 210 (WHT), and/or CKT 211 (DK BLU) and replace fuse.

Is the repair complete?

--

Go to Lumbar Support System Check

--

4

Are both the driver and the passenger seat back lumbar supports inoperative?

--

Go to Step 5

Go to Step 7

5
  1. Inspect CKT 2240 between C317 cavity C and the underhood fuse block.
  2. Inspect ground CKT 1350 between S427 and G450.

Are the circuits OK?

--

Go to Step 9

Go to Step 6

6

Repair the circuits as necessary.

Is the repair complete?

--

Go to Lumbar Support System Check

--

7
  1. Inspect the motor for overheating.
  2. Inspect for broken wires.

Are the motor and wires OK?

--

Go to Step 9

Go to Step 8

8

Repair or replace the motor and/or wires as necessary.

Is the repair complete?

--

Go to Lumbar Support System Check

--

9
  1. Do not disconnect C317 (C315 for the right side).

    2. Connect a J 39200 digital multimeter (DMM) to ground and CKT 2240 (ORN) terminal D at C317 (C315 for the right side).

  2. Test for voltage.

Is battery voltage present?

B+

Go to Step 11

Go to Step 10

10

Locate and repair the open in CKT 2240 (ORN) between C317 (C315 for the right side) and the underhhood fuse block connector C1,terminal A1.

Is the repair complete?

--

Go to Lumbar Support System Check

--

11
  1. Do not disconnect C317 (C315 for the right side).

    2. Connect a J 39200 DMM to ground and CKT 2240 (ORN) terminal C at C317 (C315 for the right side) and CKT 1350 (BLK) terminal B at C317 (C315 for the right side).

  2. Test for voltage.

Is battery voltage present?

B+

Go to Step 13

Go to Step 12

12

Locate and repair the open or high resistance in CKT 1350 (BLK) between C317 (C315 for the right side) and G450.

Is the repair complete?

--

Go to Lumbar Support System Check

--

13
  1. Access the lumbar switch.
  2. Connect a J 39200 DMM to ground and CKT 2240 (ORN) terminal H at the seat lumbar support switch.
  3. Test for voltage.

Is battery voltage present?

B+

Go to Step 15

Go to Step 14

14

Locate and repair the open in CKT 2240 (ORN) between C317 (C315 for the right side) and terminal H at the lumbar switch.

Is the repair complete?

--

Go to Lumbar Support System Check

--

15
  1. Connect a J 39200 DMM to CKT 2240 (ORN) terminal H and CKT 1350 (BLK/WHT) terminal E at the seat lumbar support switch.
  2. Test for voltage.

Is battery voltage present?

B+

Go to Step 17

Go to Step 16

16

Locate and repair the open or high resistance in CKT 1350 (BLK) between C317 (C315 for the right side) and terminal E at the lumbar switch.

Is the repair complete?

--

Go to Lumbar Support System Check

--

17
  1. Connect a J 39200 DMM to the DK BLU wire terminal F of the lumbar motor connector and connector terminal G at the lumbar switch.
  2. Test for voltage while operating the switch in the OUT/IN positions.

Is battery voltage present?

B+

Go to Step 19

Go to Step 18

18

Replace the lumbar switch.

Is the repair complete?

--

Go to Lumbar Support System Check

--

19
  1. Loosen the seat in order to access the lumbar motor connector.
  2. Connect a J 39200 DMM to the DK BLU wire at the lumbar motor connector terminal A and terminal G at the lumbar switch.
  3. Test for voltage.
  4. Operate the switch in the OUT position.

Is battery voltage present?

B+

Go to Step 21

Go to Step 20

20

Locate and repair the open or high resistance in the DK BLU wire between the lumbar motor connector terminal A and terminal F at the lumbar switch.

Is the repair complete?

--

Go to Lumbar Support System Check

--

21
  1. Connect a J 39200 DMM to the lumbar motor connector terminal B and the DK BLU wire terminal F at the lumbar support switch.
  2. Test for voltage.
  3. Operate the switch in the IN position.

Is battery voltage present?

B+

Go to Step 23

Go to Step 22

22

Locate and repair the open or high resistance in the PNK (LH) and /or WHT (RH) wire between the lumbar motor connector terminal B and terminal G at the lumbar switch.

Is the repair complete?

--

Go to Lumbar Support System Check

--

23

Replace the lumbar motor.

Is the repair complete?

--

Go to Lumbar Support System Check

--