B2425
DTC B2425 or B2430
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC B2425
- Driver Seat Heater Circuit
DTC B2430
- Passenger Seat Heater Circuit
Diagnostic Fault Information
Circuit/System Description
The left and right heated seats are controlled by the memory seat module (MSM). When active, ground is applied to the seat cushion and back heater elements through a common low side drive low reference control circuit. Battery voltage is applied to each individual heater element by the MSM through separate high side drive control circuits. The heater element control circuits are pulse width modulated to B+ by the module in order to control the seat temperature by regulating the current flow through the heater elements. The module then monitors the current flow through the heating elements and the of rate change of the temperature sensors to verify correct heated seat operation.
Conditions for Running the DTC
* The battery voltage must be between 9-16 volts.
* Heated seat operation is enabled.
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
* This DTC will clear on current status after the condition for setting the fault is corrected.
* The history DTC will clear after 100 consecutive fault-free ignition cycles have occurred.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Heated Seats Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
B2425
1. Ignition OFF, disconnect the X3 harness connector at the MSM.
2. Test for infinite resistance between the control circuit terminal B12 and ground.
• If less than the specified range, test the control circuits listed below for a short to ground:
* Driver seat cushion and seat back terminal B12
* Driver seat cushion circuit terminal B11
* Driver seat back circuit terminal B10
3. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal B12 and ground.
• If the test lamp illuminates, test the control circuits listed below for a short to voltage:
* Driver seat cushion and seat back terminal B12
* Driver seat cushion circuit terminal B11
* Driver seat back circuit terminal B10
4. If all circuits test normal, replace the MSM.
B2430
1. Ignition OFF, disconnect the X3 harness connector at the MSM.
2. Test for infinite resistance between the control circuit terminal B9 and ground.
• If less than the specified range, test the control circuits listed below for a short to ground:
* Passenger seat cushion and seat back terminal B9
* Passenger seat cushion circuit terminal B8
* Passenger seat back circuit terminal B7
3. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal B9 and ground.
• If the test lamp illuminates, test the control circuits listed below for a short to voltage:
* Passenger seat cushion and seat back terminal B9
* Passenger seat cushion circuit terminal B8
* Passenger seat back circuit terminal B7
4. If all circuits test normal, replace the MSM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Driver or Passenger Seat Back Cushion Heater Replacement (Driver or Passenger Seat Back Cushion Heater Replacement)
* Driver or Passenger Seat Cushion Heater Replacement (Driver or Passenger Seat Cushion Heater Replacement)
* Control Module References (Programming and Relearning) for MSM replacement, programming, and setup