Service Information

Volt

DTC B1925 or B2170

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC B1925 02: Driver Seat Cushion Heater Sensor Circuit Short to Ground

DTC B1925 05: Driver Seat Cushion Heater Sensor Circuit High Voltage/Open

DTC B2170 02: Passenger Seat Cushion Heater Sensor Circuit Short to Ground

DTC B2170 05: Passenger Seat Cushion Heater Sensor Circuit High Voltage/Open

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Driver Heated Seat Element Voltage Control	B242A 02	B2425 0D	B242A 01	B2425 0B, B2425 0E
Driver Heated Seat Element Ground Control	B242A 02	B2425 0D	B242A 01	B2425 0B, B2425 0E
Driver Heated Seat Cushion Temperature Sensor Signal	B1925 02	B1925 05	B1925 05	B2345 13
Driver Heated Seat Cushion Temperature Sensor Low Reference	-	B1925 05	-	B2345 13
Passenger Heated Seat Element Voltage Control	B242A 02	B2430 0D	B242A 01	B2430 0B, B2430 0E
Passenger Heated Seat Element Ground Control	B242A 02	B2430 0D	B242A 01	B2430 0B, B2430 0E
Passenger Heated Seat Cushion Temperature Sensor Signal	B2170 02	B2170 05	B2170 05	B2345 13
Passenger Heated Seat Cushion Temperature Sensor Low Reference	-	B2170 05	-	B2345 13

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 seat heating control module supplies a 5 V 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 sensor.

Conditions for Running the DTC

•	DTC B1325 must not be present.

•	The seat heating control module must be powered.

Conditions for Setting the DTC

B1925 02 or B2170 02

The temperature sensor voltage drops below 0.6 V for more than 1 second.

B1925 05 or B2170 05

The temperature sensor voltage is greater than 5 V 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

•	The current DTC will clear and set the code to history 3 seconds after the reference voltage returns to normal operating range and the vehicle is cycled Vehicle OFF then back to Vehicle ON or Vehicle in Service Mode.

•	The history DTC will clear after 40 consecutive fault-free Vehicle On cycles have occurred.

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Vehicle OFF, disconnect the harness connector at the appropriate E14B or E14D seat cushion heating element.
Test for less than 10 Ω between the low reference circuit terminal D and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit test normal, replace the K29 seat heating control module.

Vehicle in Service Mode, 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 K29 seat heating control module.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K29 seat heating control module.

If all circuits test normal, test or replace the E14 seat cushion heating element.

Component Testing

E14B or E14D Seat Cushion Heating Element

Vehicle OFF, disconnect the harness connector at the appropriate E14B or E14D seat cushion heating element.
Test for 500 Ω - 300 kΩ between the signal circuit terminal C and the low reference circuit terminal D.

⇒	If not within the specified range, replace the E14 seat cushion heating element.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Driver Seat Cushion Heater Replacement

•	Passenger Seat Cushion Heater Replacement

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