GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Body and Accessories 🢒 Seats 🢒 Power Seat Inoperative

Power Seat Inoperative DeVille w/o A45

Step

Action

Value(s)

Yes

No

1

Did you perform the entire Power Seats System Check?

--

Go to Step 2

Go to Power Seats System Check

2
  1. Disconnect the seat relay module connector C3.
  2. Connect a J 39200 digital multimeter (DMM) between the seat relay module connector C3 cavity A (RED) and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 3

Go to Step 8

3
  1. Disconnect the seat relay module connector C2.
  2. Connect a DMM between the seat relay module connector C3 cavity A (RED) and connector C2 cavity C (BLK).

Is the voltage within the specified range?

10-15 V

Go to Step 4

Go to Step 9

4
  1. Disconnect the seat switch connector.
  2. Connect a DMM between the seat relay module connector C3 cavity A (RED) and the seat switch connector cavity J (BLK).

Is the voltage within the specified range?

10-15 V

Go to Step 5

Go to Step 10

5
  1. Connect the seat relay module connector C2 and connector C3.
  2. Connect a fused jumper between the seat switch connector cavity F (GRY) and ground.

Does the entire seat move forward?

--

Go to Step 6

Go to Step 7

6

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

Is the seat switch replacement complete?

--

Go to Power Seats System Check

--

7

Replace the seat relay module.

Is the seat relay module replacement complete?

--

Go to Power Seats System Check

--

8

Repair the open in CKT 742 (RED) between splice S311 and the seat relay module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Seats System Check

--

9

Repair the open in CKT 850 (BLK) between splice S313 and the seat relay module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Seats System Check

--

10

Repair the open in CKT 50 (BLK) between splice S200 and the LH seat switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Seats System Check

--

Power Seat Inoperative Eldorado w/o A45

Step

Action

Value(s)

Yes

No

1

Did you perform the entire Power Seats System Check?

--

Go to Step 2

Go to Power Seats System Check

2

Using a test lamp, backprobe the seat switch connector from cavity H (RED) to ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 5

3

Using a test lamp, backprobe the seat switch connector from cavity H (RED) to cavity G (BLK).

Does the test lamp light?

--

Go to Power Seats System Check

Go to Step 6

4

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

Is the seat switch replacement complete?

--

Go to Power Seats System Check

--

5

Repair the open in CKT 742 (RED) between splice S311 and the seat switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Seats System Check

--

6

Repair the open in CKT 850 (BLK) between splice S313 and the seat switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Seats System Check

--

Power Seat Inoperative All Functions

Step

Action

Value(s)

Yes

No

1

Did you perform the entire Power Seats System Check?

--

Go to Step 2

Go to Power Seats System Check

2

Do the power mirrors operate properly?

--

Go to Step 4

Go to Outside Mirrors System Check in Doors

3

Do the horns operate properly?

--

Go to Step 4

Go to Step 6

4

Do the front and rear console ash tray lamps operate properly?

--

Go to Step 5

Go to Step 7

5

Repair the open in CKT 742 (RED) between splice S101 and splice S311. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Power Seats System Check

--

6

Repair the open in CKT 742 (RED) between the LH underhood fuse block and splice S311. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Power Seats System Check

--

7

Repair the open in CKT 850 (BLK) between splice S313 and ground G302. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Power Seats System Check

--

Power Seat Inoperative DeVille w A45

Step

Action

Value(s)

Yes

No

1

Did you perform the entire Power Seats: Memory System Check?

--

Go to Step 2

Go to Memory Seats System Check

2
  1. Disconnect the memory seat module (MSM) connector C2.
  2. Connect a J 39200 digital multimeter (DMM) between the MSM connector C2 cavity D (ORN) and cavity C (BLK).

Is the voltage within the specified range?

10-15 V

Go to Step 3

Go to Step 5

3
  1. Disconnect the LH seat switch connector.
  2. Connect a DMM between the battery voltage (B+) and the LH seat switch connector cavity J (BLK).

Is the voltage within the specified range?

10-15 V

Go to Step 4

Go to Step 6

4

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

Is the seat switch replacement complete?

--

Go to Step 7

--

5

Repair the open in CKT 850 (BLK) between splice S351 and the MSM. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 7

--

6

Repair the open in CKT 50 (BLK) between splice S200 and the LH seat switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 7

--

7

Perform the Power Seats System Check . Is the system check complete?

--

System OK

--

Power Seat Inoperative Eldorado w A45

Step

Action

Value(s)

Yes

No

1

Did you perform the entire Power Seats: Memory System Check?

--

Go to Step 2

Go to Memory Seats System Check

2
  1. Disconnect the memory seat module (MSM) connector C2.
  2. Connect a J 39200 digital multimeter (DMM) between the MSM connector C2 cavity D (ORN) and cavity C (BLK).

Is the voltage within the specified range?

10-15 V

Go to Step 3

Go to Step 6

3
  1. Disconnect the LH seat switch connector.
  2. Connect a DMM between the MSM connector C2 cavity D (ORN) and the LH seat switch connector cavity H (BLK).

Is the voltage within the specified range?

10-15 V

Go to Step 4

Go to Step 7

4

Test for a short to ground between the LH seat switch and the MSM in the following circuits:

    • CKT 1523 (LT GRN)
    • CKT 1522 (TAN)
    • CKT 1519 (YEL)
    • CKT 1518 (DK GRN)
    • CKT 1520 (DK BLU)
    • CKT 1521 (LT BLU)
    • CKT 1269 (GRY/BLK)
    • CKT 1270 (DK GRN/WHT)

Refer to Testing for Short to Ground in Wiring Systems.

Are the circuits OK?

--

Go to Step 5

Go to Step 8

5

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

Is the seat switch replacement complete?

--

Go to Step 9

--

6

Repair the open in CKT 850 (BLK) between splice S351 and the MSM. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

--

7

Repair the open in CKT 850 (BLK) between splice S351 and the LH seat switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

--

8

Repair the suspect wiring. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

--

9

Perform the Power Seats System Check . Is the system check complete?

--

System OK

--