Diagnostic Instructions

DTC Descriptors

DTC B2345 13: Seat Heater Disable Circuit Voltage Low / High Temperature

DTC B2345 42: Seat Heater Disable Circuit Calibration Data Set Not Programmed

DTC B2345 4B: Seat Heater Disable Circuit Calibration Not Learned

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 0D	B2508 01	B1935 0E
Left Rear Heated Seat Back Element Control	B2508 02	B1935 0D	B2508 01	B1935 0E
Left Rear Heated Seat Back Temperature Sensor Signal	B2435 02	B2435 05	B2435 05	B2345 13, B2345 42, B2345 4B
Left Rear Heated Seat Back Temperature Sensor Low Reference	--	B2435 05	--	B2345 13, B2345 42, B2345 4B
Left Rear Heated Seat Cushion Element Supply Voltage	B2508 02	B2425 0D	B2508 01	B2425 0E
Left Rear Heated Seat Cushion Element Control	B2508 02	B2425 0D	B2508 01	B2425 0E
Left Rear Heated Seat Cushion Temperature Sensor Signal	B1925 02	B1925 05	B1925 05	B2345 13, B2345 42, B2345 4B
Left Rear Heated Seat Cushion Temperature Sensor Low Reference	--	B1925 05	--	B2345 13, B2345 42, B2345 4B
Right Rear Heated Seat Back Element Supply Voltage	B2508 02	B2180 0D	B2508 01	B2180 0E
Right Rear Heated Seat Back Element Control	B2508 02	B2180 0D	B2508 01	B2180 0E
Right Rear Heated Seat Back Temperature Sensor Signal	B2440 02	B2440 05	B2440 05	B2345 13, B2345 42, B2345 4B
Right Rear Heated Seat Back Temperature Sensor Low Reference	--	B2440 05	--	B2345 13, B2345 42, B2345 4B
Right Rear Heated Seat Cushion Element Supply Voltage	B2508 02	B2430 0D	B2508 01	B2430 0E
Right Rear Heated Seat Cushion Element Control	B2508 02	B2430 0D	B2508 01	B2430 0E
Right Rear Heated Seat Cushion Temperature Sensor Signal	B2170 02	B2170 05	B2170 05	B2345 13, B2345 42, B2345 4B
Right Rear Heated Seat Cushion Temperature Sensor Low Reference	--	B2170 05	--	B2345 13, B2345 42, B2345 4B

Circuit/System Description

The left and right rear seat heating elements are controlled by a common high current relay internal to the rear heated seat module (RHSM) and the low side by individual element control circuits. The RHSM connects the seat heater element supply voltage circuits for both seats to a common reference point. This reference point is biased to approximately 2.0 volts. Before the RHSM will allow heated seat operation, it checks to see if this reference voltage is shorted to ground or battery voltage. Once the module verifies that it is not closing to a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

Conditions for Running the DTC

The heated seat system is active.

Conditions for Setting the DTC

B2345 13

Any temperature sensor input that remains below 1.5  volts for more than 1 second.

B2345 42

This DTC will set if the RHSM calibration is not programmed.

B2345 4B

This DTC will set if the RHSM calibration is out of range.

Action Taken When the DTC Sets

The heated seat function for both rear passenger seats will be disabled.

Conditions for Clearing the DTC

Reference Information

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Rear Heated Seats Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

B2345 13

1. Ignition OFF, disconnect the X2, X4 harness connectors at the RHSM.
2. Test for greater than 2.1K ohms between the signal circuit and low reference circuits listed below:

•	Left rear seat cushion terminal 9 X4 and terminal 6 X2

•	Right rear seat cushion terminal 20 X4 and terminal 8 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 appropriate seat cushion temperature sensor.

3. Test for greater than 2.0K ohms between the signal circuit and low reference circuits listed below:

•	Left rear seat back terminal 19 X4 and terminal 5 X2

•	Right rear seat back terminal 10 X4 and 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 appropriate seat back temperature sensor.

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

B2345 42 or B2345 4B

If either DTC is set, replace the RHSM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.