FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

With Memory A45 and KB6




DTC B2425 or B2430 (With Memory A45 and KB6)

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 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 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

Diagnostic Fault Information






Circuit/System Description

The left and right heated seats are controlled by the memory seat module (MSM). When active, power is applied to the seat cushion and back heater elements through a common voltage supply circuit. The heater elements are grounded by the MSM through a low side drive control circuit. The heater element control circuit is a pulse width modulated to ground by the module in order to control the seat temperature by regulating the current flow through the heater elements. The module then monitors the current flow through the heater elements and the of rate change of the temperature sensor to verify correct heated seat operation.

Conditions for Running the DTC

The MSM must be powered.

Conditions for Setting the DTC

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

By measuring the current and voltage through the seat cushion heating element every 10 seconds, the memory seat module calculates that the heating element resistance is below the minimum resistance.

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

By measuring the current and voltage through the seat cushion heating element every 10 seconds, the memory seat module calculates that the heating element resistance is above the maximum resistance.

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, 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 (Except A45) Heated/Cooled Seat SchematicsHeated/Cooled Seat Schematics (With KA1) Heated/Cooled Seat Schematics (With KA1)Heated/Cooled Seat Schematics (With KB6) Heated/Cooled Seat Schematics (With KB6)

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

Description and Operation

Heated Seats Description and Operation Heated Seats

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

B2425 0B, B2425 0C, B2425 0D, or B2425 0E

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, disconnect the harness connector at the seat back heater element.

Note:
When measuring resistance, the resistance values are based on the seat being at room temperature of 20°C (68°F).

4. Test for 0.5-1.5 ohms between control circuit terminal A and control circuit terminal F.

If not within the specified range, test or replace the seat back heater element.

5. Connect the harness connector at the seat back heater element and disconnect the X1 harness connector at the MSM.

6. Test for 2-5.5 ohms between control circuit terminal 6 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.

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

B2430 0B, B2430 0C, B2430 0D, or B2430 0E

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, disconnect the harness connector at the seat back heater element.

Note:
When measuring resistance, the resistance values are based on the seat being at room temperature of 20°C (68°F).

4. Test for 0.5-1.5 ohms between control circuit terminal A and control circuit terminal F.

If not within the specified range, test or replace the seat back heater element.

5. Connect the harness connector at the seat back heater element and disconnect the X1, X4 harness connectors at the MSM.

6. Test for 2-5.5 ohms between control circuit terminal 14 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.

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

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Driver or Passenger Seat Back Cushion Heater Replacement Driver or Passenger Seat Back Cushion Heater Replacement

* Driver or Passenger Seat Cushion Heater Replacement (Passenger) Driver or Passenger Seat Cushion Heater Replacement (Passenger)Driver or Passenger Seat Cushion Heater Replacement (Driver) Driver or Passenger Seat Cushion Heater Replacement (Driver)

* Control Module References Programming and Relearning for MSM replacement, programming and setup