LaCrosse V6-3.8L (2009)
Seat Heater: Symptom Related Diagnostic Procedures
Front Heated Seat Malfunction
Front Heated Seat Malfunction
Diagnostic Instructions
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Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
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Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
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Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure Instructions)
provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The driver and passenger heated seats are controlled by separate heated seat switches located in the HVAC control module. When a heated seat switch is
pressed, the HVAC control module sends a serial data message to the body control module (BCM) indicating the heated seat command. In response to
this signal, the BCM applies battery positive voltage through the heated seat relay control circuit energizing the relay coil. The relay closes its switch
contacts applying battery positive voltage through the element supply voltage circuit to the seat heating elements. The BCM then sends a serial data
message back to the HVAC control module to illuminate the appropriate temperature indicator.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics (See: Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Heated Seats Description and Operation (See: Description and Operation)
Electrical Information Reference
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Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics)
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Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics)
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Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics)
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Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning)
Circuit/System Verification