GM Service Manual Online
For 1990-2009 cars only

Power Seat Does Not Move Forward/Rearward without A45

Step

Action

Value(s)

Yes

No

1

Was the entire Power Seats System Check performed?

--

Go to Step 2

Go to Power Seats System Check

2

  1. Backprobe the seat switch connector with a DMM from cavity B (LT GRN) (LH) or cavity C (LT GRN) (RH) to ground.
  2. Move the forward/back switch BACK.

Is the voltage within the specified range?

10-15 V

Go to Step 3

Go to Step 4

3

  1. Backprobe the seat switch connector with a DMM from cavity E (TAN) (LH) or cavity F (TAN) (RH) to ground.
  2. Move the forward/back switch FORWARD.

Is the voltage within the specified range?

10-15 V

Go to Step 5

Go to Step 4

4

Replace the seat switch. Refer to Power Seat Switch Replacement .

Is the seat switch replacement completeI?

--

Go to Power Seats System Check

--

5

  1. Backprobe with a DMM across the forward/back motor connector cavity B (LT GRN) to ground.
  2. Move the forward/back switch BACK.

Is the voltage within the specified range?

10-15 V

Go to Step 6

Go to Step 8

6

  1. Backprobe with a DMM across the forward/back motor connector cavity A (TAN) to ground.
  2. Move the forward/back switch FORWARD.

Is the voltage within the specified range?

10-15 V

Go to Step 7

Go to Step 9

7

Replace the forward/back motor. Refer to Front Seat Adjuster Replacement .

Is the forward/back motor replacement complete?

--

Go to Power Seats System Check

--

8

Repair the open in CKT 284 (LT GRN) (LH) or CKT 290 (LT GRN) (RH) between the seat switch and the forward/back motor. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Power Seats System Check

--

9

Repair the open in CKT 285 (TAN) (LH) or CKT 296 (TAN) (RH) between the seat switch and the forward/back motor. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Power Seats System Check

--

Power Seat Does Not Move Forward/Rearward A45 with AL2

Step

Action

Value(s)

Yes

No

1

Was the entire Memory Seats System Check performed?

--

Go to Step 2

Go to Memory Seats System Check

2

  1. Turn the ignition switch to the ON position.
  2. Connect a scan tool to the data link connector (DLC).
  3. Select INPUTS from the memory seat module (MSM) DATA DISPLAY.
  4. Operate the LH entire seat switch in the FORWARD direction.

Did the scan tool indicate that the seat switch input was received?

--

Go to Step 3

Go to Step 8

3

Operate the LH entire seat switch in the BACK direction.

Did the scan tool indicate that the seat switch input was received?

--

Go to Step 4

Go to Step 9

4

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

Did the motor run?

--

Go to Step 5

Go to Step 11

5

Check for an open or short to ground in CKT 285 (TAN) between the MSM and the LH forward/back motor.

Is CKT 285 OK?

--

Go to Step 6

Go to Step 12

6

Check for an open or short to ground in CKT 284 (LT GRN) between the MSM and the LH forward/back motor.

Is CKT 284 OK?

--

Go to Step 7

Go to Step 13

7

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

Is the MSM replacement complete?

--

Go to Memory Seats System Check

--

8

  1. Disconnect the LH seat switch connector.
  2. Disconnect the memory seat module (MSM) connector C2.
  3. Connect a DMM from the LH seat switch connector cavity E (TAN) to the MSM connector C2 cavity C5 (TAN).

Is the resistance less than the specified value?

5 ohms

Go to Step 10

Go to Step 14

9

  1. Disconnect the LH seat switch connector.
  2. Disconnect the memory seat module (MSM) connector C2.
  3. Connect a DMM from the LH seat switch connector cavity B (LT GRN) to the MSM connector C2 cavity C6 (DK BLU).

Is the resistance less than the specified value?

5 ohms

Go to Step 10

Go to Step 15

10

Replace the LH seat switch. Refer to Power Seat Switch Replacement .

Is the LH seat switch replacement complete?

--

Go to Memory Seats System Check

--

11

Replace the LH forward/back motor. Refer to Front Seat Adjuster Replacement .

Is the motor replacement complete?

--

Go to Memory Seats System Check

--

12

Repair the open or short to ground in CKT 285 (TAN) between the MSM and the LH forward/back motor. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Memory Seats System Check

--

13

Repair the open or short to ground in CKT 284 (LT GRN) between the MSM and the LH forward/back motor. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Memory Seats System Check

--

14

Repair the open in CKT 1522 (TAN) between the LH seat switch and the MSM. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Memory Seats System Check

--

15

Repair the open in CKT 1523 (LT GRN) between the LH seat switch and the MSM. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Memory Seats System Check

--

Power Seat Does Not Move Forward/Rearward A45 with AC9

Step

Action

Value(s)

Yes

No

1

Was the entire Memory Seats System Check performed?

--

Go to Step 2

Go to Memory Seats System Check

2

  1. Turn the ignition switch to the ON position.
  2. Connect a scan tool to the data link connector (DLC).
  3. Select INPUTS from the memory seat module (MSM) DATA DISPLAY.
  4. Operate the LH entire seat switch in the FORWARD direction.

Did the scan tool indicate that the seat switch input was received?

--

Go to Step 3

Go to Step 8

3

Operate the LH entire seat switch in the BACK direction.

Did the scan tool indicate that the seat switch input was received?

--

Go to Step 4

Go to Step 9

4

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

Did the motor run?

--

Go to Step 5

Go to Step 11

5

Check for an open or short to ground in CKT 285 (TAN) between the MSM and the LH forward/back motor.

Is CKT 285 OK?

--

Go to Step 6

Go to Step 12

6

Check for an open or short to ground in CKT 284 (LT GRN) between the MSM and the LH forward/back motor.

Is CKT 284 OK?

--

Go to Step 7

Go to Step 13

7

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

Is the MSM replacement complete?

--

Go to Memory Seats System Check

--

8

  1. Disconnect the LH seat switch connector.
  2. Disconnect the memory seat module (MSM) connector C2.
  3. Connect a DMM from the LH seat switch connector cavity E (TAN) to the MSM connector C2 cavity A5 (TAN).

Is the resistance less than the specified value?

5 ohms

Go to Step 10

Go to Step 14

9

  1. Disconnect the LH seat switch connector.
  2. Disconnect the memory seat module (MSM) connector C2.
  3. Connect a DMM from the LH seat switch connector cavity B (LT GRN) to the MSM connector C2 cavity A6 (DK BLU).

Is the resistance less than the specified value?

5 ohms

Go to Step 10

Go to Step 15

10

Replace the LH seat switch. Refer to Power Seat Switch Replacement .

Is the LH seat switch replacement complete?

--

Go to Memory Seats System Check

--

11

Replace the LH forward/back motor. Refer to Front Seat Adjuster Replacement .

Is the motor replacement complete?

--

Go to Memory Seats System Check

--

12

Repair the open or short to ground in CKT 285 (TAN) between the MSM and the LH forward/back motor. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Memory Seats System Check

--

13

Repair the open or short to ground in CKT 284 (LT GRN) between the MSM and the LH forward/back motor. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Memory Seats System Check

--

14

Repair the open in CKT 1522 (TAN) between the LH seat switch and the MSM. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Memory Seats System Check

--

15

Repair the open in CKT 1523 (LT GRN) between the LH seat switch and the MSM. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Memory Seats System Check

--