GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 SRX 🢒 Seats 🢒 Seat Heating and Cooling 🢒 Heated Seat Switch Indicator Malfunction

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Heated Seat Back/Cushion Switch Signal

1

1

1

--

Heated Seat Back Only Mode Switch Signal

1

1

1

--

Heated Seat Back Only Mode Indicator Control

2

2

2

--

Heated Seat Back/Cushion Indicator Control

2

2

2

--

Heated Seat Cool Indicator Control

2

2

2

--

Heated Seat High Temperature Indicator Control

2

2

2

--

Heated Seat Low Temperature Indicator Control

2

2

2

--

Heated Seat Medium Temperature Indicator Control

2

2

2

--

Heated Seat Switch Low Reference

1

1

--

--

1. Heated seat inoperative

2. Heated seat switch indicator malfunction

Circuit/System Description

The driver and front passenger heated seats are controlled by separate heated seat switches. The switches are located on the door panels. When a heated seat switch is pressed, ground is momentarily applied through the switch contacts and the switch signal circuit to the door module. In response to this signal, the door module sends a serial data message to the memory seat module (MSM) indicating the heat seat request. The door module then applies voltage through the appropriate indicator control circuits to the heated seat switch illuminating the appropriate indicators.

Reference Information

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification
  1. Ignition ON, observe the heated seat switch mode indicators while pressing the heated seat switch. The appropriate indicators should illuminate when the switch is pressed.
  2. Ignition ON, observe the appropriate scan tool Door Switch Seat Indicator Cmd. parameter while pressing the heated seat switch. The reading should change between Off and On.

Circuit/System Testing
  1. Ignition OFF, disconnect the X4 harness connector at the appropriate door module.
  2. Ignition ON, verify the heated seat switch mode indicators are not illuminated.
    3. ⇒If any indicator is illuminated, test the appropriate control circuit for a short to voltage.
  3. Connect a 3A fused jumper wire between the low reference circuit terminal 4 and ground.
  4. Connect a test lamp between B+ and each control circuit listed below. Each indicator should illuminate when tested.
    5. • Medium heat indicator terminal 1
    • High heat indicator terminal 2
    • Low heat indicator terminal 9
    • Seat back and cushion indicator terminal 10
    • Seat back only mode indicator terminal 11
    ⇒If any indicator does not illuminate, replace the heated seat switch.
  5. If all indicators illuminate, replace the appropriate door module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Front Seat Heater Switch Replacement
    •  Control Module References for DDM or PDM replacement, setup, and programming