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 complete?

--

Go to Power Seats System Check

--

5

  1. Backprobe with a DMM across the seat horizontal 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 seat horizontal 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 seat horizontal motor. Refer to Seat Adjuster Motor Replacement - Power .

Is the seat horizontal 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 seat horizontal 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 seat horizontal 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 entire seat switch in the FORWARD direction.

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

--

Go to Step 3

Go to Step 8

3

Operate the entire seat switch in the BACK direction.

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

--

Go to Step 4

Go to Step 9

4

  1. Disconnect the seat horizontal 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.

Does the motor run?

--

Go to Step 5

Go to Step 11

5

Test for an open or short to ground in CKT 285 (TAN) between the MSM and the seat horizontal motor. Refer to Testing for Continuity or Testing for Short to Ground in Wiring Systems.

Is CKT 285 OK?

--

Go to Step 6

Go to Step 12

6

Test for an open or short to ground in CKT 284 (LT GRN) between the MSM and the seat horizontal motor. Refer to Testing for Continuity or Testing for Short to Ground in Wiring Systems.

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 seat switch connector.
  2. Disconnect the memory seat module (MSM) connector C2.
  3. Connect a DMM from the 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 seat switch connector.
  2. Disconnect the memory seat module (MSM) connector C2.
  3. Connect a DMM from the 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 seat switch. Refer to Power Seat Switch Replacement .

Is the seat switch replacement complete?

--

Go to Memory Seats System Check

--

11

Replace the seat horizontal motor. Refer to Seat Adjuster Motor Replacement - Power .

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 seat horizontal 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 seat horizontal 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 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 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 entire seat switch in the FORWARD direction.

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

--

Go to Step 3

Go to Step 8

3

Operate the entire seat switch in the BACK direction.

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

--

Go to Step 4

Go to Step 9

4

  1. Disconnect the seat horizontal 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.

Does the motor run?

--

Go to Step 5

Go to Step 11

5

Test for an open or short to ground in CKT 285 (TAN) between the MSM and the seat horizontal motor. Refer to Testing for Continuity or Testing for Short to Ground in Wiring Systems.

Is CKT 285 OK?

--

Go to Step 6

Go to Step 12

6

Test for an open or short to ground in CKT 284 (LT GRN) between the MSM and the seat horizontal motor. Refer to Testing for Continuity or Testing for Short to Ground in Wiring Systems.

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

Is the resistance less than the specified value?

5 ohms

Go to Step 10

Go to Step 15

10

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

Is the seat switch replacement complete?

--

Go to Memory Seats System Check

--

11

Replace the seat horizontal motor. Refer to Seat Adjuster Motor Replacement - Power .

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 seat horizontal 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 seat horizontal 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 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 seat switch and the MSM. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Memory Seats System Check

--