GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The driver seat module controls the voltage supply and the ground circuits to the driver and passenger seat heater elements. When a heated seat function is commanded active, the seat module will switch battery voltage to the heater element supply circuits, and ground is provided through low side drive control circuits. During heated seat operation both the seat back and cushion heater elements are supplied battery voltage. The seat module grounds the appropriate control circuits for driver or passenger heated seat operation, and opens or closes the active control circuits as necessary in order to maintain the desired seat temperature.

Conditions for Running the DTC

    • Battery voltage to the seat module must be within 8-17 volts.
    • Heated seat operation is attempted.

Conditions for Setting the DTC

    • One of the low side drive control circuits is shorted to voltage or ground.
    • One of the heater element voltage supply circuits is shorted to voltage or ground.

Action Taken When the DTC Sets

The seat module will disable heated seat operation.

Conditions for Clearing the DTC

    • The DTC will be stored as a history code when the fault is no longer present.
    • A history DTC will be cleared after completing 100 consecutive ignition cycles.

Diagnostic Aids

If the DTC is only found in history, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step

Action

Yes

No

Schematic Reference: Heated Seats Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you perform the Power Seat Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2

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

Does the heated seat system operate normally?

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

Go to Step 3

3

  1. Turn the ignition OFF.
  2. Disconnect the seat module connector C3.
  3. Turn the ignition ON.
  4. Connect a test lamp from the seat heater element control circuit terminal in the harness connector to ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4

Connect a test lamp from battery voltage to the seat heater element control circuit terminal in the seat module harness connector.

Does the test lamp illuminate?

Go to Step 6

Go to Step 7

5

Repair the seat heater element voltage supply or control circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 9

--

6

Repair the seat heater element voltage supply or control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 9

--

7

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

Did you find and correct the condition?

Go to Step 9

Go to Step 8

8

Replace the driver seat module. Refer to Memory Seat Control Module Replacement .

Is the repair complete?

Go to Step 9

--

9

  1. Use the scan tool in order to clear the DTCs .
  2. Operate the system within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK