B2435

DTC B2435 or B2440

Circuit Description

The driver seat module relies on inputs from thermistors installed in the driver and passenger seat backs to control heated seat temperatures. The thermistors are 2 wire sensors supplied with a 5-volt referenced signal circuit and low reference circuit from the driver seat module. Resistance through the thermistors varies with temperature causing the heated seat sensor signal circuit voltage levels to decrease as the seat back temperatures rise.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

* DTC B2435 Driver Seat Back Heater Sensor Circuit
* DTC B2440 Passenger Seat Back Heater Sensor Circuit

Conditions for Running the DTC

* The system voltage must be between 9-16 volts.
* The heated seat is in an active state.

Conditions for Setting the DTC

* The heated seat sensor signal circuit voltage to the driver seat module is greater than 4.94 volts for 30 seconds or more.
* The heated seat sensor signal circuit voltage to the driver seat module is less than 0.078 volts for 30 seconds or more.
* The heated seat sensor signal circuit input to the driver seat module indicates that the desired seat temperature has not been reached within 30 minutes after activation.

Action Taken When the DTC Sets

* The heated seat with a current status DTC will be disabled.
* When the fault is no longer present a history status DTC will be stored, and heated seat operation will be restored.

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.
* When the fault is no longer present the DTC will be a history status code.
* The history DTC will be cleared after 100 error free ignition cycles, or by using the scan tool clearing DTCs feature.

Test Description

Step 1 - Step 8:

Step 9 - Step 12:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the high voltage range.
4. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens upon performing this test, the signal circuit has a short to voltage.