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

Step

Action

Value(s)

Yes

No

1

Did you perform the Power Seats System Check?

--

Go to Step 2

Go to Heated Seats System Check

2

Inspect the DIC/HVAC fuse.

Is the DIC/HVAC fuse open?

--

Go to Step 3

Go to Step 4

3
  1. Repair a short to ground in CKT 541.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

4
  • Inspect HSEAT/LUM fuse.

Is the HSEAT/LUM fuse open?

--

Go to Step 5

Go to Step 6

5
  1. Repair a short to ground in CKT 2040.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

6
  1. Connect a test lamp.
  2. Backprobe between the driver seat heater control module connector terminal D and ground.

Does the test lamp light?

--

Go to Step 7

Go to Step 13

7
  1. Connect a test lamp.
  2. Backprobe between the driver seat heater control module connector terminals D and F.

Does the test lamp light?

--

Go to Step 8

Go to Step 14

8
  1. Turn the ignition switch to the RUN position.
  2. Connect a test lamp.
  3. Backprobe between the driver seat heater control module connector terminal C and ground.
  4. Set the heated driver seat switch to the HI and then the LO positions.

Does the test lamp light with the switch in both positions?

--

Go to Step 9

Go to Step 15

9
  1. Turn the ignition switch to the RUN position.
  2. Connect a test lamp.
  3. Backprobe between the driver seat heater control module connector terminal B and ground.
  4. Set the heated driver seat switch to the HI and then the LO positions.

Does the test lamp light with the switch in both positions?

--

Go to Step 10

Go to Step 21

10
  1. Turn the ignition switch to the OFF position.
  2. Ensure the heated driver seat switch is not set to HI or LO.
  3. Disconnect the driver seat heater control module connector.
  4. Measure the resistance between the driver seat heater control module connector terminal A and ground.

Is the resistance within the specified range?

0-2.0ohms

Go to Step 11

Go to Step 24

11
  • Measure the resistance between the driver seat heater control module connector terminal E and ground.

Is the resistance within the specified values?

3000-5000ohms

Go to Step 12

Go to Step 29

12
  1. Replace the driver seat heater control module. Refer to Heater Module Replacement .
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

13
  1. Repair the poor connection or open in CKT 2040.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

14
  1. Repair the poor connection or open in CKT 750 to G301.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

15

Observe the test lamp.

Does the test lamp light in either position?

--

Go to Step 24

Go to Step 16

16
  1. Turn the ignition switch to the RUN position.
  2. Connect a test lamp.
  3. Backprobe between the driver seat heater switch connector terminal D and ground.

Does the test lamp light?

--

Go to Step 18

Go to Step 17

17
  1. Repair the poor connection or open in CKT 541.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

18

Inspect for a poor connection or open in CKT 1462.

Did you find a poor connection or open in CKT 1462?

--

Go to Step 19

Go to Step 20

19
  1. Repair the poor connection or open in CKT 1462.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

20
  1. Replace the driver seat heater switch.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

21

Observe the test lamp.

Does the test lamp light in either position?

--

Go to Step 20

Go to Step 22

22

Inspect for a poor connection or open in CKT 1501.

Did you find a poor connection or open in CKT 1501?

--

Go to Step 23

Go to Step 20

23
  1. Repair the poor connection or open in CKT 1501.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

24
  1. Disconnect the driver seat cushion cover connector.
  2. Measure the resistance between the driver seat cushion cover connector terminals A and B.

Is the resistance within the specified range?

0-1.0ohms

Go to Step 25

Go to Step 28

25
  1. Disconnect the driver seat back cushion cover connector.
  2. Measure the resistance between the driver seat cushion cover connector terminals A and B.

Is the resistance within the specified range?

0-1.0ohms

Go to Step 26

Go to Step 27

26
  1. Repair the poor connection or open in CKTs 900, 950 or 750 between the driver seat heater control module harness connector terminal A and S330.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

27
  1. Replace the heated seat element in the driver seat cushion cover.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

28
  1. Replace the heated seat element in the driver seat back cushion cover.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

29
  1. Disconnect the driver seat cushion cover connector.
  2. Measure the resistance between the driver seat cushion cover connector terminals C and D.

Is the resistance within the specified range?

3000-5000ohms

Go to Step 30

Go to Step 31

30
  1. Repair the poor connection or open in CKT 952 or CKT 750 to S330.
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--

31
  1. Replace the heated seat thermistor in the driver seat cushion cover. Refer to Front Seat Cushion Replacement .
  2. Inspect the system.

Is the repair complete?

--

Go to Heated Seats System Check

--