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B2425



DTC B2425 or B2430

Diagnostic Instructions

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



DTC Descriptors
DTC B2425 04
- Left Seat Cushion Heater Circuit Open

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

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

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

DTC B2425 1F
- Left Seat Cushion Heater Circuit Intermittent

DTC B2430 04
- Right Seat Cushion Heater Circuit Open

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

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

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

DTC B2430 1F
- Right Seat Cushion Heater Circuit Intermittent




Diagnostic Fault Information






Circuit/System Description

The left and right rear passenger heated seats are controlled by the rear heated seat module. When active, power is applied to the seat cushion and back heater elements through a common voltage supply circuit. Each individual heater element is grounded by the heated seat module through separate low side drive control circuits. The heater element control circuits are pulse width modulated to ground by the module in order to control the seat temperatures by regulating the current flow through the heater elements. The module then monitors the current flow through the heating elements and the of rate change of the temperature sensors to verify correct heated seat operation.


Conditions for Running the DTC

The heated seat system must be active.


Conditions for Setting the DTC

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 fro up to 8.5 minutes.

B2425 0B, B2430 0B

By measuring the current and voltage output to the seat cushion heating element every 10 seconds, the rear heated seat module calculates that the heating element resistance is below the minimum resistance value of 5.4 ohms.

B2425 0C, B2430 0C

By measuring the current and voltage output to the seat cushion heating element every 10 seconds, the rear heated seat module calculates that the heating element resistance is above the maximum resistance value of 13.2 ohms.

B2425 1F, B2430 1F

The temperature sensor voltage is erratic, sudden change, or intermittent.


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.



Reference Information
Schematic Reference

Heated/Cooled Seat Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Rear Heated Seats Description and Operation (Rear Heated Seats Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Programming and Relearning (Programming and Relearning) for Scan Tool Information


Circuit/System Testing


B2425 Left Rear Heated Seat Cushion
1. Ignition OFF, disconnect the X1 harness connector at the rear heated seat module.
2. Test for less than 13.2 ohms between the seat cushion supply voltage 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.

3. Ignition OFF, disconnect the X2, X4 harness connectors at the rear heated seat module.
4. Test for 1.4K-300K ohms between the seat cushion temperature 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 cushion temperature sensor.
• If less than the specified range, test for a short between the signal and low reference circuits. If the circuits tests normal, replace the seat cushion temperature sensor.

5. Ignition OFF, connect the X1, X2, X4 harness connectors at the heated seat module.
6. Disconnect the harness connector at the seat cushion heating element/temperature sensor.
7. 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 rear 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 rear heated seat module.

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



B2430 Right Rear Heated Seat Cushion
1. Ignition OFF, disconnect the X1 harness connector at the rear heated seat module.
2. Test for less than 13.2 ohms between the seat cushion 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.

3. Ignition OFF, disconnect the X2, X4 harness connectors at the rear heated seat module.
4. Test for 1.4K-300K ohms between the seat cushion temperature sensor signal circuit terminal 20 X4 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 cushion 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 cushion temperature sensor.

5. Ignition OFF, connect the X1, X2, X4 harness connectors at the heated seat module.
6. Disconnect the harness connector at the seat cushion heating element/temperature sensor.
7. 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 rear 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 rear heated seat module.

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



Repair Instructions

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

* Rear Seat Cushion Heater Replacement (Rear Seat Cushion Heater Replacement)
* Programming and Relearning (Programming and Relearning) for the rear heated seat module replacement, setup, and programming


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