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With Memory




DTC B2425 or B2430 (w/o HP2 with Memory)

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 B2425 04

-
Left Seat Heater Cushion Circuit Open

DTC B2425 0A

-
Left Seat Heater Cushion Circuit Rate of Change Below Threshold

DTC B2425 0B

-
Left Seat Heater Cushion Circuit Current Above Threshold

DTC B2425 0C

-
Left Seat Heater Cushion Circuit Current Below Threshold

DTC B2425 0D

-
Left Seat Heater Cushion Circuit Resistance Above Threshold

DTC B2425 0E

-
Left Seat Heater Cushion Circuit Resistance Below Threshold

DTC B2425 1F

-
Left Seat Heater Cushion Circuit Intermittent

DTC B2430 04

-
Right Seat Heater Cushion Circuit Open

DTC B2430 0A

-
Right Seat Heater Cushion Circuit Rate of Change Below Threshold

DTC B2430 0B

-
Right Seat Heater Cushion Circuit Current Above Threshold

DTC B2430 0C

-
Right Seat Heater Cushion Circuit Current Below Threshold

DTC B2430 0D

-
Right Seat Heater Cushion Circuit Resistance Above Threshold

DTC B2430 0E

-
Right Seat Heater Cushion Circuit Resistance Below Threshold

DTC B2430 1F

-
Right Seat Heater Cushion Circuit Intermittent

Diagnostic Fault Information






Circuit/System Description

The driver and front passenger heated seats are controlled by the memory seat module (MSM). When active, power is applied to the seat cushion and seat back heater elements through a common voltage supply circuit. The module controls the seat temperature by providing a pulse width modulated (PWM) ground through the heated seat element control circuits to the seat 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 MSM must be powered.

Conditions for Setting the DTC

B2425 04 or B2430 04

The module does not detect a temperature change within 210 seconds.

B2425 0A or B2430 0A

The module detects that the set point temperature has not been reached within 8.5 minutes.

B2425 0B, B2425 0E, B2430 0B, or B2430 0E

By measuring output current, the module calculates that the heating element resistance is below the minimum resistance.

B2425 0C, B2425 0D, B2430 0C, or B2430 0D

By measuring output current, the module calculates that the heating element resistance is above the maximum resistance.

B2425 1F or B2430 1F

The temperature sensor voltage is erratic or changes suddenly.

Action Taken When the DTC Sets

The heated seat cushion 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 [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 (KA1) Heated Seats (KA1)Heated Seats Description and Operation (KA6) Heated Seats (KA6)

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 Control Module References for 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 a vehicle equipped with memory, refer to Circuit/System Testing below.

If the DTC set in a hybrid vehicle without memory, refer to DTC B2425 or B2430 (HP2 w/o memory).

If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2425 or B2430 (Dealer installed).

If the DTC set in the rear heated seat module, refer to DTC B2425 or B2430 (Rear seat).

Circuit/System Testing

B2425 0A, B2425 0B, B2425 0C, B2425 0D, B2425 0E, B2425 04, or B2425 1F

1. Ignition OFF, disconnect the X3 harness connector at the MSM.

2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 5 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 harness connector at the MSM and disconnect the X1 harness connector at the MSM.

Important:
Element resistance must be measured twice to ensure that all failure conditions are simulated. First with the seat unoccupied, then with the seat occupied.


4. Test for 2.0 - 8.0 omhs between control circuit terminal 14 and control circuit terminal 11.

• If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element.

• If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal replace the seat cushion heater element.

5. Disconnect the X2, X5 harness connectors at the MSM.

6. Test for 850 omhs - 300 komhs between the signal circuit terminal 1 X5 and the low reference circuit terminal 3 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.

7. Connect the X1, X2, X5 harness connectors at the MSM.

8. Disconnect the harness connector at the seat cushion heater element/temperature sensor.

9. 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 MSM.

• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.

10. If all circuits test normal, replace the MSM.

B2430 0A, B2430 0B, B2430 0C, B2430 0D, B2430 0E, B2430 04, or B2430 1F

1. Ignition OFF, disconnect the X3 harness connector at the MSM.

2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 5 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 harness connector at the MSM and disconnect the X1, X4 harness connectors at the MSM.

Important:
Element resistance must be measured twice to ensure that all failure conditions are simulated. First with the seat unoccupied, then with the seat occupied.


4. Test for 2.0 - 8.0 omhs between control circuit terminal 6 X1 and control circuit terminal 14 X4.

• If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element.

• If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal replace the seat cushion heater element.

5. Disconnect the X2, X5 harness connectors at the MSM.

6. Test for 850 omhs - 300 komhs between the signal circuit terminal 2 X5 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.

7. Connect the X1, X2, X4, X5 harness connectors at the MSM.

8. Disconnect the harness connector at the seat cushion heater element/temperature sensor.

9. Ignition ON, test for 4.8 - 5.2 V between the 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 MSM.

• 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 MSM.

10. If all circuits test normal, replace the MSM.

Repair Instructions

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

* Driver or Passenger Seat Cushion Heater Replacement (without HP2) Driver or Passenger Seat Cushion Heater ReplacementDriver or Passenger Seat Cushion Heater Replacement (with HP2) Driver or Passenger Seat Cushion Heater Replacement

* Control Module References Control Module References for the MSM replacement, setup, and programming

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