B2430
DTC B2425 or B2430
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions 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 driver and front passenger 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 MSM in order to control the seat temperature by regulating the current flow through the heater elements. The MSM then monitors the current flow through the heating elements and the rate of change of the temperature sensors to verify correct heated seat operation.
Conditions for Running the DTC
The MSM or rear heated seat module must be powered.
Conditions for Setting the DTC
B2425 04 and B2430 04
The module does not detect a temperature change within 210 seconds.
B2425 0A and B2430 0A
The module detects that the set point temperature has not been reached within 8.5 minutes.
B2425 0B and B2430 0B
By measuring the current and voltage output to the seat cushion heating element every 10 seconds, the MSM calculates that the heating element resistance is less than the minimum resistance value of 2.0 ohms.
B2425 0C and B2430 0C
By measuring the current and voltage output to the seat cushion heating element every 10 seconds, the MSM calculates that the heating element resistance is greater than the maximum resistance value of 6.5 ohms.
B2425 1F and 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.
Circuit/System Testing
B2425
1. Ignition OFF, disconnect the X1 harness connector at the MSM.
2. Ignition OFF, test for less than 10 ohms between the heater element supply voltage circuit terminal 6 and the control circuit terminal 11.
^ If greater than the specified value, 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 and X5 harness connectors at the MSM.
4. Test for 2000-10K ohms between the temperature sensor signal circuit terminal 1 and the low reference circuit terminal 3.
^ 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. Connect the X1, X2, and X5 harness connectors at the MSM.
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 MSM.
^ If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the MSM.
8. If all circuits test normal, replace the MSM.
B2430
1. Ignition OFF, disconnect the X1 and X4 harness connectors at the MSM.
2. Ignition OFF, test for less than 10 ohms between the heater element supply voltage circuit terminal 14 X1 and the control circuit terminal 14 X4.
^ If greater than the specified value, 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 and X5 harness connectors at the MSM.
4. Test for 2000-10K ohms between the temperature sensor 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.
5. Connect the X1, X2, X4 and X5 harness connectors at the MSM.
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 MSM.
^ If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the MSM.
8. If all circuits test normal, replace the MSM.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Driver Seat Cushion Heater and Passenger Seat Cushion Heater Replacement (Driver) Driver Seat Cushion Heater and Passenger Seat Cushion Heater Replacement (Passenger)