B1925
DTC B1925 or B2170
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 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/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 ignition is cycled OFF then back to ACC or RUN.
* The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Heated Seats Description and Operation (Description and Operation)
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 (Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate E14B or E14D seat cushion heating element.
2. Test for less than 10 Ohms between the low reference circuit terminal 1 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.
3. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal 2 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.
4. If all circuits test normal, test or replace the E14 seat cushion heating element.
Component Testing
E14B or E14D Seat Cushion Heating Element
1. Ignition OFF, disconnect the harness connector at the appropriate E14B or E14D seat cushion heating element.
2. Test for 500 Ohms - 300 kOhms between the signal circuit terminal 2 and the low reference circuit terminal 1.
• If not within the specified range, replace the E14 seat cushion heating element.
Note: Element resistance must be measured twice to ensure that all failure conditions are simulated. First with the seat unoccupied, then with the seat occupied.
3. Test for 0.5 - 5 Ohms between control circuit terminal 3 and control circuit terminal 4.
• If not within the specified range, replace the E14 seat cushion heating element.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Driver Seat Cushion Heater Replacement (Driver Seat Cushion Heater Replacement)
* Passenger Seat Cushion Heater Replacement (Passenger Seat Cushion Heater Replacement)
* Control Module References (Programming and Relearning) for seat heating control module replacement, setup, and programming