GM Service Manual Online
For 1990-2009 cars only

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step tests the integrity of the heated seat back only mode signal from the door module. This signal is a momentary 35 millisecond one shot pulse signal that is monitored through a momentary change in voltage when the switch is pressed. In order to accurately recognize the change in voltage, the volt meter should be stable before performing this test.

Step

Action

Value(s)

Yes

No

Schematic Reference: Driver Seat Schematics or 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

Verify that the Heated/Cooled Seat Inoperative - Back Only Mode complaint is present.

Does the seat back only mode operate as described in the Heated/Cooled Seats Description and Operation?

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

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Seat Back Heat Mode Switch parameter in the Door Module data list.
  4. With the heated seat ON, press the BACK ONLY switch.

Does the Back Only Switch parameter change state?

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Go to Step 8

Go to Step 4

4

  1. Disconnect the heated/cooled seat switch.
  2. Connect a 3-amp fused jumper wire between the heated/cool seat switch supply voltage circuit of the switch connector and the seat back only mode switch signal circuit of the switch connector.
  3. With a scan tool, observe the Seat Back Heat Mode Switch parameter.

Does the Seat Back Heat Mode Switch parameter change state?

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Go to Step 7

Go to Step 5

5

Test the seat back heat mode switch signal circuit between the heated/cooled seat switch and the door control module for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 12

Go to Step 6

6

Inspect for poor connections at the harness connector of the door control 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 12

Go to Step 9

7

Inspect for poor connections at the harness connector of the heated/cooled 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 12

Go to Step 10

8

Inspect for poor connections at the harness connector of the climate control 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 12

Go to Step 11

9

Replace the door control module. Refer to Door Control Module Replacement in Doors.

Did you complete the replacement?

--

Go to Step 12

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10

Replace the heated/cooled seat switch. Refer to Heated and Cooled Seat Switch Replacement .

Did you complete the replacement?

--

Go to Step 12

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11

Replace the climate control seat module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2