Dealer Installed
DTC B2435 or B2440 (Dealer Installed)
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 B2435 02
-
Left Seat Back Heater Sensor Circuit Short to Ground
DTC B2435 05
-
Left Seat Back Heater Sensor Circuit Short to Battery or Open
DTC B2440 02
-
Right Seat Back Heater Sensor Circuit Short to Ground
DTC B2440 05
-
Right Seat Back Heater Sensor Circuit Short to Battery or Open
Diagnostic Fault Information
Circuit/System Description
The heated seat temperature sensor that set this diagnostic trouble code (DTC) is located in the seat cushion just under the seat cover with the seat heating element. The heated seat module (HSM) supplies a 5 V reference voltage through the temperature sensor signal circuit and a ground through the low reference circuit to the sensor. The HSM monitors the voltage of the sensor signal circuit to determine the temperature of the seat. The temperature sensor varies in resistance based on the temperature of the heating element causing the signal voltage to change. Once the seat reaches the set temperature, the HSM will then cycle the control circuits of the heating elements ON and OFF in order to maintain the desired seat temperature based on the feedback voltage from the sensor.
Conditions for Running the DTC
The HSM must be powered.
Conditions for Setting the DTC
B2435 02 or B2440 02
The temperature sensor voltage drops below 0.8 V for more than 1 second.
B2435 05 or B2440 05
The temperature sensor voltage is greater than 5 V for more than 1 second.
Action Taken When the DTC Sets
The heated seat back function for the affected seat will be disabled.
Conditions for Clearing the DTC
* The current DTC will clear 3 seconds after the reference voltage returns to normal operating range, and the ignition is cycled OFF then back to ACC or RUN.
* A history DTC will clear after 50 ignition cycles or with a scan tool using the clear DTCs function.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics [1][2]Electrical DiagramsHeated/Cooled Seat Schematics [1][2]Electrical DiagramsHeated/Cooled Seat Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
Description and Operation
Heated Seats Description and Operation 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 Control Module References for scan tool information
Circuit/System Testing
B2435 02 or B2435 05
1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
2. Test for 850 omhs - 300 komhs between the signal circuit terminal 19 X4 and the low reference circuit terminal 5 X2.
• If less than the specified range, test for a short between the signal and low reference circuits. If the circuits test normal, replace the seat back heater element/temperature sensor.
• If greater than the specified range, test the signal and low reference circuits for a short to voltage or an open/high resistance. If the circuits test normal, replace the seat back heater element/temperature sensor.
3. Connect the X2, X4 harness connectors at the HSM.
4. Disconnect the harness connector at the seat back heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HSM.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
6. If all circuits test normal, replace the HSM.
B2440 02 or B2440 05
1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
2. Test for 850 omhs - 300 komhs between the signal circuit terminal 10 X4 and the low reference circuit terminal 7 X2.
• If less than the specified range, test for a short between the signal and low reference circuits. If the circuits test normal, replace the seat back heater element/temperature sensor.
• If greater than the specified range, test the signal and low reference circuits for a short to voltage or an open/high resistance. If the circuits test normal, replace the seat back heater element/temperature sensor.
3. Connect the X2, X4 harness connectors at the HSM.
4. Disconnect the harness connector at the seat back heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HSM.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
6. If all circuits test normal, replace the HSM.
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
* Control Module References Control Module References for the HSM replacement, setup, and programming