DTC B2425 or B2430. Buick Lucerne 2007

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2007 🢒 Lucerne 🢒 DTC 🢒 DTC B2425 or B2430

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

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	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Driver Heated Seat Back Element Supply Voltage	B2508 02	B1935 0C, B1935 0D	B2345 00, B2508 01	B1935 0B, B1935 0E
Driver Heated Seat Back Element Supply Control	B2345 00, B2508 02	B1935 0C, B1935 0D	B2345 00, B2508 01	B1935 0B, B1935 0E
Driver Heated Seat Back Temperature Sensor Signal	B2435 02	B1935 04, B1935 1F, B2435 0D	B1935 04, B1935 1F, B2435 0D	B1935 0A, B2345 13, B2345 42, B2345 4B
Driver Heated Seat Back Temperature Sensor Low Reference	--	B1935 04, B1935 1F, B2435 0D	--	B2345 13, B2345 42, B2345 4B
Driver Heated Seat Cushion Element Supply Voltage	B2508 02	B2425 0C, B2425 0D	B2345 00, B2508 01	B2425 0B, B2425 0E
Driver Heated Seat Cushion Element Control	B2345 00, B2508 02	B2425 0C, B2425 0D	B2345 00, B2508 01	B2425 0B, B2425 0E
Driver Heated Seat Cushion Temperature Sensor Signal	B1925 02, B2425 1F	B1925 05, B2425 04, B2425 1F	B1925 05, B2425 04, B2425 1F	B2345 13, B2345 42, B2345 4B, B2425 0A
Driver Heated Seat Cushion Temperature Sensor Low Reference	--	B1925 05, B2425 04, B2425 1F	--	B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Back Element Supply Voltage	B2508 02	B2180 0C, B2180 0D	B2345 00, B2508 01	B2180 0B, B2180 0E
Passenger Heated Seat Back Element Control	B2345 00, B2508 02	B2180 0C, B2180 0D	B2345 00, B2508 01	B2180 0B, B2180 0E
Passenger Heated Seat Back Temperature Sensor Signal	B2440 02	B2180 04, B2180 1F, B2440 05	B2180 04, B2180 1F, B2440 05	B2180 0A, B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Back Temperature Sensor Low Reference	--	B2180 04, B2180 1F, B2440 05	--	B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Cushion Element Supply Voltage	B2508 02	B2430 0C, B2430 0D	B2345 00, B2508 01	B2430 0B, B2430 0E
Passenger Heated Seat Cushion Element Control	B2345 00, B2508 02	B2430 0C, B2430 0D	B2345 00, B2508 01	B2430 0B, B2430 0E
Passenger Heated Seat Cushion Temperature Sensor Signal	B2170 02, B2430 1F	B2430 04, B2430 1F, B2170 05	B2430 04, B2430 1F, B2170 05	B2345 13, B2345 42, B2345 4B, B2430 0A
Passenger Heated Seat Cushion Temperature Sensor Low Reference	--	B2430 04, B2430 1F, B2170 05	--	B2345 13, B2345 42, B2345 4B

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

Connector End View Reference

Heated/Cooled Seat Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

•	Scan Tool Data List

•	Scan Tool Data Definitions

Circuit/System Testing

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

Ignition OFF, disconnect the C1 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).

Test for 2.0-6.5 ohms between the supply voltage circuit terminal 14 and the control circuit terminal 11.

⇒	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/temperature sensor.

⇒	If less than the specified range, test for a short between the supply voltage circuit and the control circuit. If the circuits test normal, replace the seat cushion heating element/temperature sensor.

Ignition OFF, disconnect the C2, C5 harness connectors at the MSM.
Test for 2.2K-300K ohms between the signal circuit terminal 1 C5 and the low reference circuit terminal 3 C2.

⇒	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 heating element/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 heating element/temperature sensor.

Ignition OFF, connect the C1, C2, C5 harness connectors at the MSM.
Disconnect the harness connector at the seat cushion heating element/temperature sensor.
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. If the circuit tests normal, replace the MSM.

If all circuits test normal, replace the MSM.

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

Ignition OFF, disconnect the C1, C4 harness connectors at the MSM.