GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Power Seats Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2

  1. Start the engine and allow to idle.
  2. Turn the heated seat switch to the low and high positions.

Does the heated seat operate properly in low and high modes?

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

Go to Step 3

3

Is the heated seat inoperative in both low and high modes?

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Go to Step 4

Go to Step 6

4

  1. Turn the ignition off.
  2. Test and repair the battery positive voltage supply circuit to the heater control module for an open or short to ground. Refer to Circuit Testing and Wiring Repairs or Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 19

Go to Step 5

5

Test and repair the heated seat system ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs or Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 19

Go to Step 6

6

  1. Start the engine and allow to idle.
  2. Using a DMM test for voltage with the heated seat switch in the high and low positions while backprobing the following heated seat control module connector terminals:
  3. • heated seat switch high/low signal circuit
    • heated seat switch on/off signal circuit

Is voltage present on these circuits in both switch positions?

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Go to Step 10

Go to Step 7

7

  1. Disconnect the heated seat switch connector.
  2. Connect a test lamp from the voltage supply circuit terminal in the heated seat switch connector to ground.
  3. Start the engine and allow to idle.

Does the test lamp illumniate?

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Go to Step 8

Go to Step 9

8

Test and repair the following circuits for an open or high resistance:

    • heated seat switch high/low signal circuit
    • heated seat switch on/off signal circuit

Refer to Circuit Testing and Wiring Repairs or Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 19

Go to Step 16

9

Test and repair the voltage supply circuit to the heated seat switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs or Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 19

Go to Step 18

10

  1. Disconnect the heated seat control module.
  2. Test the resistance to ground from the heated seat thermistor signal circuit terminal in the control module connector.

Is the resistance greater than the specified value?

5K ohms

Go to Step 11

Go to Step 12

11

Test the resistance to ground from the heated seat element supply circuit terminal in the control module connector.

Is the resistance less than the specified value?

200 ohms

Go to Step 17

Go to Step 13

12

Test and repair the heated seat thermistor signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and corect the condition?

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Go to Step 19

Go to Step 14

13

Test and repair the heated seat element supply and ground circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs or Connector Repairs in Wiring Systems.

Did you find and corect the condition?

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Go to Step 19

Go to Step 15

14

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

Is the repair complete?

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Go to Step 19

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15

Test continuity through the heated seat elements and replace as necessary. Refer to Front Seat Heater Element Replacement .

Is the repair complete?

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Go to Step 19

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16

Replace the heated seat switch. Refer to Heated Seat Switch Replacement .

Is the repair complete?

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Go to Step 19

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17

Replace the heated seat control module. Refer to Front Seat Heater Control Module Replacement .

Is the repair complete?

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Go to Step 19

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18

Replace the BCM. Refer to

Is the repair complete?

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Go to Step 19

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19

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3