GM Service Manual Online
For 1990-2009 cars only

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

Driver Heated Seat Element Supply Voltage

B2345 00, B2508 02

B2425 0C, B2425 0D

B2345 00, B2508 01

--

Driver Heated Seat Element Control

B2345 00, B2508 02

B2425 0C, B2425 0D

B2345 00, B2508 01

--

Driver Heated Seat Temperature Sensor Signal

B1925 02

B1925 05, B2425 04, B2425 1F

B1925 05, B2425 04, B2425 1F

B2345 13, B2345 42, B2345 4B

Driver Heated Seat Temperature Sensor Low Reference

--

B1925 05, B2425 04, B2425 1F

--

B2345 13, B2345 42, B2345 4B

Passenger Heated Seat Element Supply Voltage

B2345 00, B2508 02

B2430 0C, B2430 0D

B2345 00, B2508 01

--

Passenger Heated Seat Element Control

B2345 00, B2508 02

B2430 0C, B2430 0D

B2345 00, B2508 01

--

Passenger Heated Seat Temperature Sensor Signal

B2170 02

B2170 05, B2430 04, B2430 1F

B2170 05, B2430 04, B2430 1F

B2345 13, B2345 42, B2345 4B

Passenger Heated Seat Temperature Sensor Low Reference

--

B2170 05, B2430 04, B2430 1F

--

B2345 13, B2345 42, B2345 4B

Circuit/System Description

The driver and front passenger heated seats are controlled by separate heated seat switches. Both switches are located in the climate control panel (CCP). When a heated seat switch is pressed, the CCP sends a serial data message to the heated seat module (HSM) indicating the heated seat request. In response to this signal, the HSM activates the heated seat by applying battery voltage to the seat heating elements. The HSM then sends a serial data message back to the CCP commanding it to illuminate the appropriate seat temperature indicator.

Reference Information

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Heated/Cooled Seat Connector End Views

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

Ignition ON, observe the appropriate scan tool Heated Seat Module parameter listed below while pressing the heated seat switch. The reading should change between Off and Back and Cushion.

    • Driver Seat HVC Mode
    • Passenger Seat HVC Mode
If not the specified value, replace the HVAC control module.
If the reading changes between Off and Back and Cushion, the heated seat is inoperative, and there are NO DTCs set, replace the HSM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for HVAC control module and HSM replacement, setup, and programming