B242A

DTC B242A

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 seat heating control module controls the seat heating operation for both the driver and front passenger seats. The module controls the heating elements 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 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 then continues to monitor the heating elements for a shorted circuit.

Conditions for Running the DTC

* DTC B1325 must not be present.

* The seat heating control module must be powered.

Conditions for Setting the DTC

B242A 01

The seat heating control module detects a short to voltage on the heater element control circuits.

B242A 02

The 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 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 Electrical Diagrams

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly - Primary

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 Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the K29 seat heating control module.

2. Test for infinite resistance between the control circuit terminals listed below and ground:

* Terminal 3

* Terminal 5

• If less than infinite resistance
Repair the short to ground on the circuit.

• If infinite resistance

3. Ignition ON.

4. Test for less than 1 V between the control circuit terminals listed below and ground:

* Terminal 3

* Terminal 5

• If 1 V or greater
Repair the short to voltage on the circuit.

• If less than 1 V

5. Replace the K29 seat heating control module.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

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