B2170
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 Instructionsprovides an overview of each diagnostic category.
DTC Descriptors
DTC B1925 02
- Left Seat Cushion Heater Sensor Circuit Shorted to Ground
DTC B1925 05
- Left Seat Cushion Heater Sensor Circuit Shorted to Battery or Open
DTC B2170 02
- Right Seat Heater Cushion Sensor Circuit Shorted to Ground
DTC B2170 05
- Right Seat Heater Cushion Sensor Circuit Shorted 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 rear heated seat module (RHSM) supplies a 5 V reference voltage through the temperature sensor signal circuit and a ground through the low reference circuit to the sensor. The RHSM 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 RHSM 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
The RHSM must be powered.
Conditions for Setting the DTC
B1925 02 or B2170 02
The temperature sensor voltage drops below 0.80 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 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 Diagrams
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Heated Seats 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 Relearningfor scan tool information
Circuit/System Verification
Verify the type of vehicle and the heated seat system for which the DTC set.
If the DTC set in the rear heated seat module, refer to Circuit/System Testing below.
If the DTC set in a vehicle equipped with memory, refer to DTC B1925 or B2170 (w/o HP2 with memory).
If the DTC set in a hybrid or a non-hybrid vehicle without memory, refer to DTC B1925 or B2170 (HP2 or dealer installed w/o memory).
Circuit/System Testing
B1925 02, B1925 05
1. Ignition OFF, disconnect the X2, X4 harness connectors at the RHSM.
2. Test for 850 Ohms - 300 kOhms between the signal circuit terminal 9 X4 and the low reference circuit terminal 6 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 cushion 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 cushion heater element/temperature sensor.
3. Connect the X2, X4 harness connectors at the RHSM.
4. Disconnect the harness connector at the seat cushion 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 RHSM.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM.
6. If all circuits test normal, replace the RHSM.
B2170 02 or B2170 05
1. Ignition OFF, disconnect the X2, X4 harness connectors at the RHSM.
2. Test for 850 Ohms - 300 kOhms between the signal circuit terminal 20 X4 and the low reference circuit 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 seat cushion 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 cushion heater element/temperature sensor.
3. Connect the X2, X4 harness connectors at the RHSM.
4. Disconnect the harness connector at the seat cushion 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 RHSM.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM.
6. If all circuits test normal, replace the RHSM.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Rear Seat Cushion Heater Replacement Rear Seat Cushion Heater Replacement
* Control Module References Programming and Relearningfor the RHSM replacement, setup, and programming