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Home >> Buick Truck >> 2009 >> Enclave FWD V6-3.6L >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> B Code Charts >> B2425 >> With Memory A45

With Memory A45




DTC B2425 or B2430 (With Memory A45)

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 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 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. Each individual heater element is grounded by the MSM 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 temperature 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 MSM must be powered.

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 for up to 8.5 minutes.

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

By measuring the current and voltage output to the seat cushion heating element every 10 seconds, the memory seat module calculates that the heating element resistance is below the minimum resistance value of 2.0 ohms.

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

By measuring the current and voltage output to the seat cushion heating element every 10 seconds, the memory seat module calculates that the heating element resistance is above the maximum resistance value of 6.5 ohms.

B2425 1F, B2430 1F

The temperature sensor voltage is erratic or change 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 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) (Except A45)Heated/Cooled Seat Schematics (A45 with KA1) (A45 with KA1)Heated/Cooled Seat Schematics (A45 with KB6) (A45 with KB6)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Heated Seats Description and Operation (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

Control Module References (Programming and Relearning) for scan tool information

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


4. Test for 5.0-10.5 ohms between control circuit terminal 6 and control circuit terminal 11.

• If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal, replace the seat cushion heating element.
• If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heating element.

5. Ignition OFF, disconnect the X2, X5 harness connectors at the MSM.
6. Test for 3.3K-300K ohms between the signal circuit terminal 1 X5 and the low reference circuit terminal 3 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.

7. Ignition OFF, connect the X1, X2, X5 harness connectors at the MSM.
8. Disconnect the harness connector at the seat cushion heating element/temperature sensor.
9. Ignition ON, test for 4.8-5.2 volts 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.

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


4. Test for 5.0-10.7 ohms between control circuit terminal 14 X1 and control circuit terminal 14 X4.

• If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal, replace the seat cushion heating element.
• If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heating element.

5. Ignition OFF, disconnect the X2, X5 harness connectors at the MSM.
6. Test for 3.3K-300K ohms between the signal circuit terminal 2 X5 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 test normal, replace the seat cushion temperature sensor.

7. Ignition OFF, connect the X1, X2, X4, X5 harness connectors at the MSM.
8. Disconnect the harness connector at the seat cushion heating element/temperature sensor.
9. Ignition ON, test for 4.8-5.2 volts 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 (Driver) (Driver or Passenger Seat Cushion Heater Replacement (Driver))Driver or Passenger Seat Cushion Heater Replacement (Passenger) (Driver or Passenger Seat Cushion Heater Replacement (Passenger))
* Control Module References (Programming and Relearning) for MSM replacement, setup, and programming

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