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B2425



DTC B2425 or B2430

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B2425 04
- Left Seat Heater Circuit Open

DTC B2425 0A
- Left Seat Heater Circuit Rate of Change Below Threshold

DTC B2425 0B
- Left Seat Heater Circuit Current Above Threshold

DTC B2425 0C
- Left Seat Heater Circuit Current Below Threshold

DTC B2425 1F
- Left Seat Heater Circuit Intermittent

DTC B2430 04
- Right Seat Heater Circuit Open

DTC B2430 0A
- Right Seat Heater Circuit Rate of Change Below Threshold

DTC B2430 0B
- Right Seat Heater Circuit Current Above Threshold

DTC B2430 0C
- Right Seat Heater Circuit Current Below Threshold

DTC B2430 1F
- Right Seat Heater Circuit Intermittent

Diagnostic Fault Information






Circuit/System Description

Both, the driver and front passenger heated seats are controlled by the heated seat module that is located under the driver seat cushion. When the heated seat is active, the module applies power through a common voltage supply circuit to the seat heater elements. The module controls the seat temperature by providing a pulse width modulation (PWM) ground through the seat heater element control circuit to the heater elements. The module then monitors the current flow through the heating elements and the rate of change of the temperature sensor to verify correct heated seat operation.

Conditions for Running the DTC

The heated seat module must be powered and the heated seat must be enabled.

Conditions for Setting the DTC

The following conditions exist for more than 1 second:

B2425 04, B2430 04

The module does not detect a temperature change for up to 210 seconds.

B2425 0A, B2430 0A

The module detects that the set point temperature has not been reached for up to 8.5 minutes.

B2425 0B, B2430 0B

By measuring current and voltage output to the seat heating elements every 10 seconds, the heated seat module calculates that the heating element resistance is below the minimum resistance.

B2425 0C, B2430 0C

By measuring current and voltage output to the seat heating elements every 10 seconds, the heated seat module calculates that the heating element resistance is above the maximum resistance.

B2425 1F, B2430 1F

The temperature sensor voltage is erratic or changes suddenly.

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 clears when the malfunction is no longer present, and the power mode changes to OFF then back to ACC or RUN.
* The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Circuit/System Testing

B2425 Left Seat Heater Circuit

1. Ignition OFF, disconnect the harness connector at the seat back heating element.
2. Test for less than 5.0 ohms of resistance between the supply voltage circuit terminal A and the control circuit terminal B.

If greater than the specified range, replace the seat back heating element.

3. Connect the harness connector at the seat back heating element.
4. Disconnect the (X1) harness connector at the heated seat module.
5. Test for less than 5.0 ohms of resistance between the supply voltage circuit terminal 3 and the control circuit terminal 5.

If greater than the specified range, test the supply voltage circuit and the control circuit for an open/high resistance. If the circuits test normal, replace the seat cushion heating element.

6. Disconnect the (X2, X4) harness connectors at the heated seat module.

Important: If the resistance is measured with the seat still warm, the resistance may vary within the specified range depending on the temperature of the seat.

7. Test for 1.9K-300K ohms of resistance between the sensor signal circuit terminal 9 (X4) and the low reference circuit terminal 6 (X2).

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 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 temperature sensor.

8. Ignition OFF, connect the (X1, X2, X4) harness connectors at the heated seat module.
9. Disconnect the harness connector at the seat cushion heating element/temperature sensor.
10. Ignition ON, test for 4.8-5.2 volts between the temperature sensor 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 heated seat module.
If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the heated seat module.

11. If all circuits test normal, replace the heated seat module.

B2430 Right Seat Heater Circuit

1. Ignition OFF, disconnect the harness connector at the seat back heating element.
2. Test for less than 5.0 ohms of resistance between the supply voltage circuit terminal A and the low reference circuit terminal B.

If greater than the specified range, replace the seat back heating element.

3. Connect the harness connector at the seat back heating element.
4. Disconnect the (X1) harness connector at the heated seat module.
5. Test for less than 5.0 ohms of resistance between the supply voltage circuit terminal 6 and the control circuit terminal 2.

If greater than the specified range, test the supply voltage circuit and the control circuit for an open/high resistance. If the circuits test normal, replace the seat cushion heating element.

6. Disconnect the (X2, X4) harness connectors at the heated seat module.

Important: If the resistance is measured with the seat still warm, the resistance may vary within the specified range depending on the temperature of the seat.

7. Test for 1.9K-300K ohms of resistance between the sensor signal circuit terminal 20 (C4) and the low reference circuit terminal 8 (X2).

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 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 temperature sensor.

8. Ignition OFF, connect the (X1, X2, X4) harness connectors at the heated seat module.
9. Disconnect the harness connector at the seat cushion heating element/temperature sensor.
10. Ignition ON, test for 4.8-5.2 volts between the temperature sensor 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 heated seat module.
If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the heated seat module.

11. If all circuits test normal, replace the heated seat module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Driver Seat and Passenger Seat Back Cushion Heater Replacement (Non-Fold Flat) Driver Seat and Passenger Seat Back Cushion Heater Replacement (Fold Flat)
* Driver Seat and Passenger Seat Cushion Heater Replacement (With Passenger Presence System) Driver Seat and Passenger Seat Cushion Heater Replacement (Without Passenger Presence System)