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

Heated Seat Inoperative Driver Heated Seat Is Inop

Step

Action

Value(s)

Yes

No

1

Was the Heated Seat System Check performed?

--

Go to Step  2

Go to Heated Seats System Check

2
  1. Disconnect the driver seat heater relay K55 connector.
  2. Use a DMM in order to measure the voltage between terminal 2 of the driver seat heater relay K55 connector and ground.

Does the voltage measure at the specified value?

B+

Go to Step  4

Go to Step  3

3
  1. Locate an open or high resistance in CKT A240.
  2. Repair the open or the high resistance in CKT A240.

Is the repair complete?

--

Go to Step  15

--

4
  1. Turn the ignition switch to the ON position.
  2. Use the DMM in order to measure the voltage between terminal 6 of the driver seat heater relay K55 connector and a known good ground.

Does the voltage measured at the specified value?

B+

Go to Step  6

Go to Step  5

5
  1. Locate an open or high resistance in CKT X320.
  2. Repair the open or the high resistance in CKT X320.

Is the repair complete?

--

Go to Step  15

--

6

Use the DMM in order to measure the resistance between terminal 4 of the driver seat heater relay K55 connector and ground.

Does the resistance measure within the specified range?

Less than 5 ohms

Go to Step  8

Go to Step  7

7
  1. Locate an open or a high resistance in CKT F240.
  2. Repair the open or the high resistance in CKT F240.

Is the repair complete?

--

Go to Step  15

--

8
  1. Press the driver seat heater switch.
  2. Use the DMM in order to measure the voltage between terminal 5 of the driver seat heater relay K55 connector and ground while holding the driver seat heater switch.

Does the voltage measure at the specified value?

B+

Go to Step  10

Go to Step  9

9
  1. Locate an open or a high resistance in CKT FA90 and/or CKT X39.
  2. Repair the open or the high resistance in CKT FA90 and/or CKT X39.
  3. If these circuits are OK, replace the driver seat heater switch. Refer to Instrument Panel Switch Replacement in Instrument Panel, Gauges, and Console.

Is the repair complete?

--

Go to Step  15

--

10
  1. Connect the driver seat heater relay K55.
  2. Disconnect connector C315D from connector C315.
  3. Press the driver seat heater switch.
  4. Use the DMM in order to measure the voltage between terminal 6 of connector C315 and ground.

Does the voltage measure at the specified value?

B+

Go to Step  12

Go to Step  11

11
  1. Locate an open or a high resistance in CKT FA9.
  2. Repair the open or the high resistance in CKT FA9.
  3. If CKT FA9 is OK, replace the driver seat heater relay K55.

Is the repair complete?

--

Go to Step  15

--

12

Use the DMM in order to measure the resistance between terminal 5 of connector C315 and ground.

Does the resistance measure within the specified range?

Less than 5 ohms

Go to Step  14

Go to Step  13

13
  1. Locate an open or a high resistance in CKT F39.
  2. Repair the open or the high resistance in CKT F39.

Is the repair complete?

--

Go to Step  15

--

14

Replace the driver seat cushion heater and/or the driver seat back cushion heater. Refer to Driver Seat and Passenger Seat Cushion Heater Replacement and/or Driver Seat and Passenger Seat Back Cushion Heater Replacement .

Is the repair complete?

--

Go to Step  15

--

15
  1. Reconnect all of the connectors and the components that were disconnected.
  2. Verify that the driver heated seat operates properly.

Does the driver heated seat operate properly?

--

Go to Heated Seats System Check

Go to Step  1

Heated Seat Inoperative Passenger Heated Seat Is Inop

Step

Action

Value(s)

Yes

No

1

Was the Heated Seat System Check performed?

--

Go to Step  2

Go to Heated Seats System Check

2
  1. Disconnect the passenger seat heater relay K56 connector.
  2. Use a DMM in order to measure the voltage between terminal 2 of the passenger seat heater relay K56 connector and ground.

Does the voltage measured at the specified value?

B+

Go to Step  4

Go to Step  3

3
  1. Locate an open or high resistance in CKT A241.
  2. Repair the open or the high resistance in CKT A241.

Is the repair complete?

--

Go to Step  15

--

4
  1. Turn the ignition switch to the ON position.
  2. Use the DMM in order to measure the voltage between terminal 6 of the passenger seat heater relay K56 connector.

Does the voltage measure at the specified value?

B+

Go to Step  6

Go to Step  5

5
  1. Locate an open or high resistance in CKT X321.
  2. Repair the open or the high resistance in CKT X321.

Is the repair complete?

--

Go to Step  15

--

6

Use the DMM in order to measure the resistance between terminal 4 of the passenger seat heater relay K56 connector and ground.

Does the resistance measure within the specified range?

Less than 5 ohms

Go to Step  8

Go to Step  7

7
  1. Locate an open or a high resistance in CKT F241.
  2. Repair the open or the high resistance in CKT F241.

Is the repair complete?

--

Go to Step  15

--

8
  1. Press and hold the passenger seat heater switch.
  2. Use the DMM in order to measure the voltage between terminal 5 of the passenger seat heater relay K56 connector and ground while holding the heater switch.

Does the voltage measure at the specified value?

B+

Go to Step  10

Go to Step  9

9
  1. Locate an open or a high resistance in CKT FB70 and/or CKT X42.
  2. Repair the open or the high resistance in CKT FB70 and/or CKT X42.
  3. If both CKTs are OK, replace the passenger seat heater switch . Refer to Instrument Panel Switch Replacement in Instrument Panel, Gauges, and Console.

Is the repair complete?

--

Go to Step  15

--

10
  1. Connect the passenger seat heater relay K56.
  2. Disconnect connector C316D from connector C316.
  3. Press the passenger seat heater switch.
  4. Use the DMM in order to measure the voltage between terminal 6 of connector C316 and ground.

Does the voltage measure at the specified value?

B+

Go to Step  12

Go to Step  11

11
  1. Locate an open or a high resistance in CKT FB7.
  2. Repair the open or the high resistance in CKT FB7.
  3. If CKT FB7 is OK, replace the passenger seat heater relay K56

Is the repair complete?

--

Go to Step  15

--

12

Use the DMM in order to measure the resistance between terminal 5 of connector C316 and ground.

Does the resistance measure within the specified range?

Less than 5 ohms

Go to Step  14

Go to Step  13

13
  1. Locate an open or a high resistance in CKT F38.
  2. Repair the open or the high resistance in CKT F38.

Is the repair complete?

--

Go to Step  15

--

14

Replace the passenger seat cushion heater and/or the passenger seat back cushion heater. Refer to Driver Seat and Passenger Seat Cushion Heater Replacement and/or Driver Seat and Passenger Seat Back Cushion Heater Replacement .

Is the repair complete?

--

Go to Step  15

--

15
  1. Reconnect all of the connectors and the components that were disconnected.
  2. Verify that the passenger heated seat operates properly.

Does the passenger heated seat operate properly?

--

Go to Heated Seats System Check

Go to Step  1