2010 Cadillac CTS Sedan AWD V6-3.6L Page 499
The MSM detects a short to voltage on the heater element supply voltage circuit or control circuit.
B2508 02
The MSM detects a short to ground on the heater element supply voltage circuit or control circuit.
Action Taken When the DTC Sets
The heated seat function for both the driver and passenger seats will be disabled.
Conditions for Clearing the DTC
* The current DTC will clear and set a history code 3 seconds after the reference voltage returns to normal operating range and the ignition is
cycled OFF then back to ACC or RUN.
* The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics (See: Body and Frame/Seats/Seat Temperature Element/Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Heated/Vented Seat Description and Operation (See: Body and Frame/Seats/Seat Temperature Element/Description and Operation)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the X1, X4 harness connectors at the MSM.
2. Test for infinite resistance between the control circuit terminal 6 X1 and ground.
瀚慖f not the specified value, test the control circuits for a short to ground.
3. Test for infinite resistance between the control circuit terminal 14 X1 and ground.
瀚慖f not the specified value, test the control circuits for a short to ground.
4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 6 X1 and ground.
瀚慖f the test lamp illuminates, test the control circuits for a short to voltage.
5. Verify that a test lamp does not illuminate between the control circuit terminal 14 X1 and ground.
瀚慖f the test lamp illuminates, test the control circuits for a short to voltage.
6. If all circuits test normal, replace the MSM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Driver or Passenger Seat Back Cushion Heater Replacement (KA1) (See: Body and Frame/Seats/Seat Temperature Element/Service and
Repair/Driver or Passenger Seat Back Cushion Heater Replacement (KA1))
* Driver Seat Cushion Heater Replacement (KA1) (See: Body and Frame/Seats/Service and Repair/Driver Seat Cushion Heater Replacement
(KA1))
* Passenger Seat Cushion Heater Replacement (KA1) (See: Body and Frame/Seats/Service and Repair/Passenger Seat Cushion Heater
