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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 DeVille 🢒 Body and Accessories 🢒 Seats 🢒 Power Seat Inoperative in One Direction

Power Seat Inoperative in One Direction w/o A45

Step

Action

Value(s)

Yes

No

1

Did you perform the Power Seats System Check?

--

Go to Step 2

Go to Power Seats System Check

2
  1. Disconnect the left seat switch connector.
  2. Operate the left seat switch in the inoperative position.
  3. Connect a J 39200 digital multimeter (DMM) between the left seat switch cavity J (BLK) and the appropriate left seat switch cavity:
    4. • Rear vertical up: cavity C (YEL)
    • Rear vertical down: cavity D (LT BLU)
    • Front vertical up: cavity G (DK GRN)
    • Front vertical down: cavity H (DK BLU)
    • Entire seat forward: cavity F (GRY)
    • Entire seat back: cavity E (BRN)
    • Recline forward: cavity B (LT GRN)
    • Recline back: cavity A (LT BLU)

Is the resistance within the specified value?

0-2 ohms

Go to Step 3

Go to Step 8

3
  1. Connect the left seat switch connector.
  2. Disconnect the left seat relay module connector C1.
  3. Operate the left seat switch in the inoperative position.
  4. Connect a DMM between ground and the appropriate left seat relay module connector cavity:
    5. • Rear vertical up: cavity 1 (YEL)
    • Rear vertical down: cavity 12 (LT BLU)
    • Front vertical up: cavity 17 (DK GRN)
    • Front vertical down: cavity 16 (BK BLU)
    • Entire seat forward: cavity 2 (GRY)
    • Entire seat back: cavity 15 (BRN)
    • Recline forward: cavity 11 (LT GRN)
    • Recline back: cavity 14 (LT BLU)

Is the resistance less than the specified value?

5 ohms

Go to Step 4

Go to Step 9

4
  1. Disconnect the suspect seat motor.
  2. Connect a fused jumper between battery positive voltage (B+) and one of the seat motor cavities.
  3. Connect a fused jumper between the other seat motor cavity and ground.

Does the motor run?

--

Go to Step 5

Go to Step 10

5
  1. Disconnect the left seat relay module connector C3.
  2. Connect a DMM between the suspect seat motor cavity and the appropriate left seat relay module cavity:
    3. • Rear vertical: connector C3 cavity B and motor cavity B (YEL)
    • Front vertical: connector C3 cavity C and motor cavity A (DK BLU)
    • Forward/back: connector C3 cavity E and motor cavity B (LT GRN)
    • Recline: connector C3 cavity D and motor cavity B (LT GRN)

Is the resistance less than the specified value?

5 ohms

Go to Step 6

Go to Step 11

6
  1. Disconnect the left seat relay module connector C3.
  2. Connect a DMM between the suspect seat motor cavity and the appropriate left seat relay module cavity:
    3. • Rear vertical: connector C3 cavity B and motor cavity B (YEL)
    • Front vertical: connector C3 cavity C and motor cavity A (DK BLU)
    • Forward/back: connector C3 cavity E and motor cavity B (LT GRN)
    • Recline: connector C3 cavity D and motor cavity B (LT GRN)

Is the resistance less than the specified value?

5 ohms

Go to Step 7

Go to Step 12

7

Replace the left seat relay module.

Is the repair complete?

--

Go to Power Seats System Check

--

8

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

Is the repair complete?

--

Go to Power Seats System Check

--

9

Repair the open in the appropriate circuit between the left seat relay module and the left seat switch:

    • Rear vertical up: CKT 1519 (YEL)
    • Rear vertical down: CKT 1521 (LT BLU)
    • Front vertical up: CKT 1518 (DK GRN)
    • Front vertical down: CKT 1520 (BK BLU)
    • Entire seat forward: CKT 613 (GRY)
    • Entire seat back: CKT 617 (BRN)
    • Recline forward: CKT 276 (LT GRN)
    • Recline back: CKT 277 (LT BLU)

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Seats System Check

--

10

Replace the suspect seat motor. Refer to Seat Adjuster Motor Replacement - Power or Recliner Motor Replacement - Front Power .

Is the repair complete?

--

Go to Power Seats System Check

--

11

Repair the open in the appropriate circuit between the left seat relay module and the suspect motor:

    • Rear vertical: CKT 282 (YEL)
    • Front vertical: CKT 287 (DK BLU)
    • Forward/back: CKT 284 (LT GRN)
    • Recline: CKT 276 (LT GRN)

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Seats System Check

--

12

Repair the open in the appropriate circuit between the left seat relay module and the suspect motor:

    • Rear vertical: CKT 283 (LT BLU)
    • Front vertical: CKT 286 (DK GRN)
    • Forward/back: CKT 285 (TAN)
    • Recline: CKT 277 (LT BLU)

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Seats System Check

--

Power Seat Inoperative in One Direction DeVille w/A45

Step

Action

Value(s)

Yes

No

1

Did you perform the Memory Seats System Check?

--

Go to Step 2

Go to Memory Seats System Check

2
  1. Turn the ignition switch to the OFF position.

    2. Important: The connector is located under the left seat. Ensure that the connector remains grounded during testing.

  2. Enter mode 1 diagnostics by grounding the memory seat module (MSM) diagnostic connector.
    3. • One beep confirms entrance to mode 1 diagnostics.
    • All of the seat and the recliner motions are disabled during mode 1 diagnostics.

Does the MSM beep once when entering mode 1 diagnostics?

--

Go to Step 3

Go to Step 7

3

Operate the left seat switch in the inoperative position.

Does the MSM beep once when the switch was moved to the inoperative position?

--

Go to Step 8

Go to Step 4

4
  1. Disconnect the left seat switch connector C1.
  2. Operate the left seat switch in the inoperative position.
  3. Connect a J 39200 digital multimeter (DMM) between the left seat switch connector cavity J (BLK) and the appropriate left seat switch connector cavity:
    4. • Rear vertical up: cavity C (YEL)
    • Rear vertical down: cavity D (LT BLU)
    • Front vertical up: cavity G (DK GRN)
    • Front vertical down: cavity H (BK BLU)
    • Entire seat forward: cavity F (GRY)
    • Entire seat back: cavity E (BRN)
    • Recline forward: cavity B (LT GRN)
    • Recline back: cavity A (LT BLU)

Is the resistance less than the specified value?

5 ohms

Go to Step 5

Go to Step 6

5

Repair the open in the appropriate wiring:

    • Rear vertical up: CKT 1519 (YEL)
    • Rear vertical down: CKT 1521 (LT BLU)
    • Front vertical up: CKT 1518 (DK GRN)
    • Front vertical down: CKT 1520 (DK BLU)
    • Entire seat forward: CKT 613 (GRY)
    • Entire seat back: CKT 617 (BRN)
    • Recline forward: CKT 276 (LT GRN)
    • Recline back: CKT 277 (LT BLU)

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 11

--

6

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

Is the repair complete?

--

Go to Step 11

--

7
  1. Inspect for proper power and ground to the MSM.
  2. Inspect for proper terminal contact at the MSM connectors.
  3. If all of the items are OK, replace the MSM. Refer to Memory Seat Control Module Replacement .

Is the repair complete?

--

Go to Step 11

--

8
  1. Disconnect the suspect seat motor connector.
  2. Connect a fused jumper between battery positive voltage (B+) and one of the seat motor cavities.
  3. Connect a fused jumper between the other seat motor cavity and ground.

Does the motor run?

--

Go to Step 9

Go to Step 10

9

Repair the open or short to ground in the appropriate wiring:

    • Rear vertical: CKT 282 (YEL) or CKT 283 (LT BLU)
    • Front vertical: CKT 286 (DK GRN) or CKT 287 (DK BLU)
    • Forward/back: CKT 284 (LT GRN) or CKT 285 (TAN)
    • Recline: CKT 276 (LT GRN) or CKT 277 (LT BLU)

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 11

--

10

Replace the suspect seat motor. Refer to Seat Adjuster Motor Replacement - Power or Recliner Motor Replacement - Front Power .

Is the repair complete?

--

Go to Step 11

--

11

Perform the Memory Seats System Check .

Is the system check complete?

--

System OK

--

Power Seat Inoperative in One Direction Eldorado w/A45

Step

Action

Value(s)

Yes

No

1

Did you perform the Memory Seats System Check?

--

Go to Step 2

Go to Memory Seats System Check

2
  1. Turn the ignition switch to the OFF position.

    2. Important: The connector is located under the left seat. Ensure that the connector remains grounded during testing.

  2. Enter mode 1 diagnostics by grounding the memory seat module (MSM) diagnostic connector.
    3. • One beep confirms entrance to mode 1 diagnostics.
    • All of the seat and the recliner motions are disabled during mode 1 diagnostics.

Does the MSM beep once when entering mode 1 diagnostics?

--

Go to Step 3

Go to Step 7

3

Operate the left seat switch in the inoperative position.

Does the MSM beep once when the switch was moved to the inoperative position?

--

Go to Step 8

Go to Step 4

4
  1. Disconnect the left seat switch connector C1.
  2. Operate the left seat switch in the inoperative position.
  3. Connect a J 39200 digital multimeter (DMM) between the left seat switch connector cavity H (BLK) and the appropriate left seat switch connector cavity:
    4. • Rear vertical up: cavity F (YEL)
    • Rear vertical down: cavity E (LT BLU)
    • Front vertical up: cavity B (DK GRN)
    • Front vertical down: cavity A (DK BLU)
    • Entire seat forward: cavity D (TAN)
    • Entire seat back: cavity C (LT GRN)
    • Recline forward: cavity M (GRY/BLK)
    • Recline back: cavity K (DK GRN/WHT)

Is the resistance less than the specified value?

5 ohms

Go to Step 5

Go to Step 6

5

Repair the open in the appropriate wiring:

    • Rear vertical up: CKT 1519 (YEL)
    • Rear vertical down: CKT 1521 (LT BLU)
    • Front vertical up: CKT 1518 (DK GRN)
    • Front vertical down: CKT 1520 (DK BLU)
    • Entire seat forward: CKT 1522 (TAN)
    • Entire seat back: CKT 1523 (LT GRN)
    • Recline forward: CKT 1269 (GRY/BLK)
    • Recline back: CKT 1270 (DK GRN/WHT)

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 11

--

6

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

Is the repair complete?

--

Go to Step 11

--

7
  1. Inspect for proper power and ground to the MSM.
  2. Inspect for proper terminal contact at the MSM connectors.
  3. If all of the items are OK, replace the MSM. Refer to Memory Seat Control Module Replacement .

Is the repair complete?

--

Go to Step 11

--

8
  1. Disconnect the suspect seat motor connector.
  2. Connect a fused jumper between battery positive voltage (B+) and one of the seat motor cavities.
  3. Connect a fused jumper between the other seat motor cavity and ground.

Does the motor run?

--

Go to Step 9

Go to Step 10

9

Repair the open or short to ground in the appropriate wiring:

    • Rear vertical: CKT 282 (YEL) or CKT 283 (LT BLU)
    • Front vertical: CKT 286 (DK GRN) or CKT 287 (DK BLU)
    • Forward/back: CKT 284 (LT GRN) or CKT 285 (TAN)
    • Recline: CKT 276 (LT GRN) or CKT 277 (LT BLU)

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 11

--

10

Replace the suspect seat motor. Refer to Seat Adjuster Motor Replacement - Power or Recliner Motor Replacement - Front Power .

Is the repair complete?

--

Go to Step 11

--

11

Perform the Memory Seats System Check .

Is the system check complete?

--

System OK

--