With KA6
DTC B242A (With KA6)
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 B242A 01
- Seat Heaters Common Circuit Short to Battery
DTC B242A 02
- Seat Heaters Common Circuit Short to Ground
Diagnostic Fault Information
Circuit/System Description
The rear seat heating control module controls seat heating operation for both left and right rear seats. The heating elements are controlled through individual high side and low side control circuits. The low side control circuits for both seats are connected to a common reference point internal to the module. This reference point is biased to approximately 2.5 V. Before the rear seat heating control module will allow heated seat operation, it checks to see if this biased voltage is shorted to ground or voltage. Once the module verifies that it is not closing to a shorted heating element, it allows for heated seat operation. The module will then continue to monitor the heating elements for a shorted circuit.
Conditions for Running the DTC
* DTC B1325 must not be present.
* The rear seat heating control module must be powered.
Conditions for Setting the DTC
B242A 01
The rear seat heating control module detects a short to voltage on the heater element control circuits
B242A 02
The rear seat heating control module detects a short to ground on the heater element control circuits.
Action Taken When the DTC Sets
The heated seat function for both rear 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 40 consecutive fault-free ignition cycles have occurred.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Rear Heated Seats Description and Operation (Rear Heated Seats)
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
1. Ignition OFF, disconnect the X2 harness connector at the K29R rear seat heating control module.
2. Test for infinite resistance between the control circuit terminal 3 and ground.
• If not the specified value, test the control circuit for a short to ground.
3. Test for infinite resistance between the control circuit terminal 5 and ground.
• If not the specified value, test the control circuit for a short to ground.
4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 3 and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage.
5. Verify that a test lamp does not illuminate between the control circuit terminal 5 and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage.
6. If all circuits test normal, replace the K29R rear seat heating control module.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for rear seat heating control module replacement, setup, and programming