GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Schematic Reference: Driver Seat Schematics , Passenger Seat Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Start the engine.
  2. Attempt to operate the heated seat in the high and low modes.

Does the system operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Install a scan tool.
  2. Observe the appropriate Heated Seat Sw. parameter in the seat module Input/Output data list.
  3. Start the engine.
  4. Operate the heated seat switch in the high and low modes.

Does the scan tool display On while the switch is in the high and low positions?

--

Go to Step 4

Go to Step 5

4

  1. Observe the Seat Heat Sensor parameter in the seat module Sensor Data list.
  2. Start the engine.
  3. Operate the heated seat switch in the high mode.

Is the Seat Heat Sensor parameter greater than the specified value?

1 V

Go to Step 7

Go to Step 6

5

  1. Disconnect the heated seat switch connector.
  2. Using a DMM measure the voltage at the 5-volt switch supply circuit terminal in the harness connector.

Is the voltage at or near the specified value?

5 V

Go to Step 10

Go to Step 9

6

  1. Disconnect the heated seat cushion 4-way connector.
  2. Using a DMM measure the resistance through the heat sensor.

Is the resistance within the specified values?

3K-11K ohms

Go to Step 11

Go to Step 15

7

  1. Disconnect the heated seat cushion 4-way connector.
  2. Using a DMM measure the resistance through the seat heater elements.

Is the resistance within the specified values?

2-4 ohms

Go to Step 12

Go to Step 8

8

  1. Disconnect the seat back heater element 2-way connector.
  2. Using a DMM measure the resistance through the seat back heater element.

Is the resistance within the specified values?

1-2 ohms

Go to Step 15

Go to Step 16

9

Test the 5-volt supply circuit to the heated seat switch for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 14

10

Test the heated seat switch high/low signal circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 13

11

Test the seat heat sensor low reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 14

12

Test the seat heater element voltage supply and control circuits in the seat harness for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 14

13

Inspect for poor connections at the harness connector of the heated seat switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 17

14

Inspect for poor connections at the harness connector of the seat module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 18

15

Inspect for poor connections at the harness connector of the seat cushion heater element. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 19

16

Inspect for poor connections at the harness connector of the seat back heater element. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 20

17

Replace the heated seat switch. Refer to Front Seat Heater Switch Replacement .

Is the repair complete?

--

Go to Step 21

--

18

Replace the driver seat module (DSM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Is the repair complete?

--

Go to Step 21

--

19

Replace the seat cushion heater element. Refer to Driver Seat and Passenger Seat Cushion Heater Replacement .

Is the repair complete?

--

Go to Step 21

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20

Replace the seat back heater element. Refer to Driver Seat and Passenger Seat Back Cushion Heater Replacement .

Is the repair complete?

--

Go to Step 21

--

21

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2