GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Riviera 🢒 Body and Accessories 🢒 Seats 🢒 Heated Seat Inoperative

Step

Action

Value(s)

Yes

No

1

Was the entire Heated Seats System Check performed?

--

Go to Step  2

Go to Heated Seats System Check

2
  1. Disconnect the heated seat module connector C1.
  2. Connect a test lamp from the heated seat module connector C1 cavity B (RED) to ground.

Does the test lamp light?

--

Go to Step  3

Go to Step  Overdrive16

3
  1. Turn the ignition switch to the RUN position.
  2. Connect a test lamp from the heated seat module connector C1 cavity A (BRN) to ground.

Does the test lamp light?

--

Go to Step  4

Go to Step  17

4

Connect a test lamp from the heated seat module connector C1 cavity B (RED) to cavity E (BLK) (left) or cavity E (BLK/WHT) (right).

Does the test lamp light?

--

Go to Step  5

Go to Step  18

5
  1. Turn the ignition switch to the OFF position.
  2. Connect a J 39200 digital multimeter (DMM) from the heated seat module connector C1 cavity C (LT BLU) (left) or cavity C (LT BLU/BLK) to ground.
  3. Press the seat heat switch.

Is the resistance less than the specified value?

5 ohms

Go to Step  9

Go to Step  6

6

Test for an open in CKT 1462 (LT BLU) (left) or CKT 1505 (LT BLU/BLK) (right) between the heated seat module and the appropriate component:

    • Left Oldsmobile: Left seat/lock switch
    • Left Buick: Outside mirror switch
    • Right Oldsmobile: Right seat/lock switch
    • Right Buick: Right heated seat switch
        Refer to Testing for Continuity in Wiring Systems.

Is CKT 1462 or CKT 1505 OK?

--

Go to Step  7

Go to Step  25

7
    • Left Oldsmobile: Test for an open in CKT 151 (BLK/WHT) between the left seat/lock switch and S212.
    • Left Buick: Test for an open in CKT 150 (BLK) between the outside mirror switch and S290.
    • Right Oldsmobile: Test for an open in CKT 151 (BLK/WHT) between the right seat/lock switch and S212.
    • Right Buick: Test for an open in CKT 151 (BLK/WHT) between the right heated seat switch and S212.

Refer to Testing for Continuity in Wiring Systems.

Is CKT 150 or CKT 151 OK?

--

Go to Step  8

Go to Step  25

8

Replace the suspect switch:

    • Left Oldsmobile: Left seat/lock switch
    • Left Buick: Outside mirror switch
    • Right Oldsmobile: Right seat/lock switch
    • Right Buick: Right heated seat switch

Is the repair complete?

--

Go to Heated Seats System Check

--

9
  1. Disconnect the heated seat module connector C2.
  2. Disconnect the heated seat module connector C3.
  3. Connect a J 39200 DMM from the heated seat module connector C3 cavity A (BLK) to cavity B (BLK).

Is the resistance less than the specified value?

10 ohms

Go to Step  10

Go to Step  19

10

Connect a J 39200 DMM from the heated seat module connector C3 cavity A (BLK) to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step  20

Go to Step  11

11

Important: : If the resistance is measured with the seat still warm, the resistance may vary outside of the specified range. The thermistor resistance may vary outside of the specified range since the thermistor resistance varies with temperature.

With the seat at room temperature, connect a J 39200 DMM from the heated seat module connector C3 cavity C (BLK) to D (BLK).

Is the resistance within the specified range?

850-115 ohms

Go to Step  12

Go to Step  19

12

Connect a J 39200 DMM from the heated seat module connector C3 cavity C (BLK) to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step  20

Go to Step  13

13

Connect a J 39200 DMM from the heated seat module connector C2 cavity A (BLK) to cavity B (BLK).

Is the resistance less than the specified value?

10 ohms

Go to Step  14

Go to Step  21

14

Connect a J 39200 DMM from the heated seat module connector C2 cavity A (BLK) to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step  22

Go to Step  15

15

Replace the heated seat module.

Is the repair complete?

--

Go to Heated Seats System Check

--

16

Repair the open in CKT 742 (RED) between S362 and the heated seat module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heated Seats System Check

--

17

Repair the open in CKT 41 (BRN) between S365 and the heated seat module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heated Seats System Check

--

18

Repair the open in CKT 150 (BLK) between the heated seat module and S290 (left) or CKT 151 (BLK/WHT) between the heated seat module and S212 (right). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heated Seats System Check

--

19

Test for an open in the heated seat cushion wiring. Refer to Testing for Continuity in Wiring Systems.

Is the wiring OK?

--

Go to Step  23

Go to Step  25

20

Test for a short to ground in the heated seat cushion wiring. Refer to Testing for Short to Ground in Wiring Systems.

Is the wiring OK?

--

Go to Step  23

Go to Step  25

21

Test for an open in the heated seat back wiring. Refer to Testing for Continuity in Wiring Systems.

Is the wiring OK?

--

Go to Step  24

Go to Step  25

22

Test for a short to ground in the heated seat back wiring. Refer to Testing for Short to Ground in Wiring Systems.

Is the wiring OK?

--

Go to Step  24

Go to Step  25

23

Replace the heated seat cushion. Refer to Front Seat Heater Element Replacement .

Is the repair complete?

--

Go to Heated Seats System Check

--

24

Replace the heated seat back. Refer to Front Seat Back Cushion Cover and Cushion Pad Replacement .

Is the repair complete?

--

Go to Heated Seats System Check

--

25

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

Is the repair complete?

--

Go to Heated Seats System Check

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