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Front Heated Seat Malfunction (Without Memory A45)

Front Heated Seat Malfunction (Without Memory A45)

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 Control Terminal 3 X2 B242A 02 B2425 0D B242A 01 B2425 0B, B2425 0E
Driver Heated Seat Element Control Terminal 1 X2 B242A 02 B2425 0D B242A 01 B2425 0B, B2425 0E
Driver Heated Seat Temperature Sensor Signal B1925 02 B1925 05 B1925 05 B2345 13
Driver Heated Seat Temperature Sensor Low Reference - B1925 05 - B2345 13
Passenger Heated Seat Element Control Terminal 5 X2 B242A 02 B2430 0D B242A 01 B2430 0B, B2430 0E
Passenger Heated Seat Element Control Terminal 2 X2 B242A 02 B2430 0D B242A 01 B2430 0B, B2430 0E
Passenger Heated Seat Temperature Sensor Signal B2170 02 B2170 05 B2170 05 B2345 13
Passenger Heated Seat Temperature Sensor Low Reference - B2170 05 - B2345 13


Circuit/System Description

The driver and front passenger heated seats are controlled by separate heated seat switches that are located with the radio/HVAC controls. When a heated seat switch is pressed, a serial data message is sent from the radio/HVAC controls to the HVAC control module indicating the heated seat command. The HVAC control module serves as a gateway to transmit the message to the seat heating control module via the serial data line. In response to this message, the seat heating control module applies battery voltage through the element supply voltage circuit to the appropriate seat heating elements. The seat heating control module then sends a serial data message back to the HVAC control module to gateway the information to the radio/HVAC controls to either illuminate or turn off the appropriate temperature indicator.

Reference Information

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated/Vented Seat 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 scan tool Driver Seat Heating/Venting/Cooling Mode parameter while pressing the driver seat HEAT switch. The reading should change between Off and Back & Cushion.

2. If not the specified value, replace the A20 radio/HVAC control.

3. Check the scan tool Passenger Seat Heating/Venting/Cooling Mode parameter while pressing the passenger seat HEAT switch. The reading should change between Off and Back & Cushion.

4. If not the specified value, replace the A20 radio/HVAC control.

5. If all scan tool parameter readings test normal, there are no DTCs set, and the driver and/or passenger heated seat is inoperative, replace the K29 seat heating control module.


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


• Radio Control Assembly Replacement

• Control Module References for seat memory control module replacement, setup, and programming