Diagnostic Instructions

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	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Left rear heated seat back element supply voltage	B2508 02	B1935 0C, B1935 0D	B2345 00, B2508 01	B1935 0B, B1935 0E
Left rear heated seat back element control	B2345 00, B2508 02	B1935 0C, B1935 0D	B2345 00, B2508 01	B1935 0B, B1935 0E
Left rear heated seat back temperature sensor signal	B2435 02	B1935 04, B1935 1F, B2435 0D	B1935 04, B1935 1F, B2435 0D	B1935 0A, B2345 13, B2345 42, B2345 4B
Left rear heated seat back temperature sensor low reference	--	B1935 04, B1935 1F, B2435 0D	--	B2345 13, B2345 42, B2345 4B
Left rear heated seat cushion element supply voltage	B2508 02	B2425 0C, B2425 0D	B2345 00, B2508 01	B2425 0B, B2425 0E
Left rear heated seat cushion element control	B2345 00, B2508 02	B2425 0C, B2425 0D	B2345 00, B2508 01	B2425 0B, B2425 0E
Left rear heated seat cushion temperature sensor signal	B1925 02, B2425 1F	B1925 05, B2425 04, B2425 1F	B1925 05, B2425 04, B2425 1F	B2345 13, B2345 42, B2345 4B, B2425 0A
Left rear heated seat cushion temperature sensor low reference	--	B1925 05, B2425 04, B2425 1F	--	B2345 13, B2345 42, B2345 4B
Right rear heated seat back element supply voltage	B2508 02	B2180 0C, B2180 0D	B2345 00, B2508 01	B2180 0B, B2180 0E
Right rear heated seat back element control	B2345 00, B2508 02	B2180 0C, B2180 0D	B2345 00, B2508 01	B2180 0B, B2180 0E
Right rear heated seat back temperature sensor signal	B2440 02	B2180 04, B2180 1F, B2440 05	B2180 04, B2180 1F, B2440 05	B2180 0A, B2345 13, B2345 42, B2345 4B
Right rear heated seat back temperature sensor low reference	--	B2180 04, B2180 1F, B2440 05	--	B2345 13, B2345 42, B2345 4B
Right rear heated seat cushion element supply voltage	B2508 02	B2430 0C, B2430 0D	B2345 00, B2508 01	B2430 0B, B2430 0E
Right rear heated seat cushion element control	B2345 00, B2508 02	B2430 0C, B2430 0D	B2345 00, B2508 01	B2430 0B, B2430 0E
Right rear heated seat cushion temperature sensor signal	B2170 02, B2430 1F	B2430 04, B2430 1F, B2170 05	B2430 04, B2430 1F, B2170 05	B2345 13, B2345 42, B2345 4B, B2430 0A
Right rear heated seat cushion temperature sensor low reference	--	B2430 04, B2430 1F, B2170 05	--	B2345 13, B2345 42, B2345 4B

Circuit/System Description

The heated seat temperature sensor that set this diagnostic trouble code (DTC) is located in the seat back just under the seat cover with the seat heating element. The rear heated seat module (RHSM) supplies a separate 5-volt reference voltage through the temperature sensor signal circuit and a ground through the low reference circuit to the sensor. The module 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 module will then cycle the control circuit of the heating elements ON and OFF in order to maintain the desired seat temperature based on the feedback voltage from the sensors.

Conditions for Running the DTC

The heated seat system must be active.

Conditions for Setting the DTC

The temperature sensor voltage drops below 0.80 volt for more than 1 second.

Action Taken When the DTC Sets

The heated seat function for the affected seat will be disabled.

Conditions for Clearing the DTC

Reference Information

Schematic Reference

Rear Seat Schematics

Connector End View Reference

Power Seat Connector End Views

Electrical Information Reference

Scan Tool Reference

Circuit/System Testing

B2435 02 or B2435 05

1. Ignition OFF, disconnect the C2, C4 harness connectors at the RHSM.
2. Test for 1.4K-300K ohms between the signal circuit terminal 19 C4 and the low reference circuit terminal 5 C2.

⇒	If greater than the specified range, test the signal circuit and low reference circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the seat back temperature sensor.

⇒	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 temperature sensor.

3. Ignition OFF, connect the C2, C4 harness connectors to the RHSM.
4. Disconnect the harness connector at the seat back heating element/temperature sensor.
5. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal C and ground.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM.

⇒	If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the RHSM.

6. If all circuits test normal, replace the RHSM.

B2440 02 or B2440 05

1. Ignition OFF, disconnect the C2, C4 harness connectors at the RHSM.
2. Test for 1.4K-300K ohms between the signal circuit terminal 10 C4 and the low reference circuit terminal 7 C2.

⇒	If greater than the specified range, test the signal circuit and low reference circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the seat back temperature sensor.

⇒	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 temperature sensor.

3. Ignition OFF, connect the C2, C4 harness connectors to the RHSM.
4. Disconnect the harness connector at the seat back heating element/temperature sensor.
5. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal C and ground.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM.

⇒	If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the RHSM.

6. If all circuits test normal, replace the RHSM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.