B2425
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 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 Resistance Above Threshold
DTC B2425 0E
- Left Seat Heater Cushion 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 Resistance Above Threshold
DTC B2430 0E
- Right Seat Heater Cushion Resistance Below Threshold
DTC B2430 1F
- Right Seat Heater Cushion Circuit Intermittent
Diagnostic Fault Information
Circuit/System Description
Both, the driver and front passenger heated seats are controlled by the heated seat module that is located under the driver seat cushion. When the heated seat is active, the module applies power through a common voltage supply circuit to the seat heater elements. The module controls the seat temperature by providing a pulse width modulation (PWM) ground through the seat heater element control circuit to the heater elements. The module then monitors the current flow through the heating elements and the rate of change of the temperature sensor to verify correct heated seat operation.
Conditions for Running the DTC
The heated seat module must be powered and the heated seat must be enabled.
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 and 0E, B2430 0B and 0E
By measuring current and voltage output to the seat heating elements every 10 seconds, the heated seat module calculates that the heating element resistance is below the minimum resistance.
B2425 0C and 0D, B2430 0C and 0D
By measuring current and voltage output to the seat heating elements every 10 seconds, the heated seat module calculates that the heating element resistance is above the maximum resistance.
B2425 1F, B2430 1F
The temperature sensor voltage is erratic or changes 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 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 0A, B2425 0B, B2425 0C, B2425 0D, B2425 0E, B2425 04, or B2425 1F
1. Ignition OFF, disconnect the harness connector at the seat back heating element.
Important: When measuring the resistance, all of the resistance values below are based on the seat being at room temperature of 20°C (68°F).
2. Test for 1.64-5.54 ohms between the control circuit terminal A and the control circuit terminal B.
^ If not within the specified range, replace the seat back heating element.
3. Connect the harness connector at the seat back heating element.
4. Disconnect the X1 harness connector at the heated seat module.
5. Test for 1.64-5.54 ohms between the control circuit terminal 3 and control circuit terminal 5.
^ 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.
6. Disconnect the X2, X4 harness connectors at the heated seat module.
7. Test for 1.9K-300K ohms between the signal circuit terminal 9 X4 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 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 temperature sensor.
8. Ignition OFF, connect the X1, X2, X4 harness connectors at the heated seat module.
9. Disconnect the harness connector at the seat cushion heating element/temperature sensor.
10. 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 heated seat module.
^ If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the heated seat module.
11. If all circuits test normal, replace the heated seat module.
B2430 0A, B2430 0B, B2430 0C, B2430 0D, B2430 0E, B2430 04, or B2430 1F
1. Ignition OFF, disconnect the harness connector at the seat back heating element.
Important: When measuring the resistance, all of the resistance values below are based on the seat being at room temperature of 20°C (68°F).
2. Test for 1.64-5.76 ohms between the control circuit terminal A and the control circuit terminal B.
^ If not within the specified range, replace the seat back heating element.
3. Connect the harness connector at the seat back heating element.
4. Disconnect the X1 harness connector at the heated seat module.
5. Test for 1.64-5.76 ohms between the control circuit terminal 6 and the control circuit terminal 2.
^ 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.
6. Disconnect the X2, X4 harness connectors at the heated seat module.
7. Test for 1.9K-300K ohms between the signal circuit terminal 20 X4 and the low reference circuit terminal 8 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 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 temperature sensor.
8. Ignition OFF, connect the X1, X2, X4 harness connectors at the heated seat module.
9. Disconnect the harness connector at the seat cushion heating element/temperature sensor.
10. 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 heated seat module.
^ If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the heated seat module.
11. If all circuits test normal, replace the heated seat module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Driver Seat and Passenger Seat Back Cushion Heater Replacement (Impala)
* Driver Seat and Passenger Seat Cushion Heater Replacement (Impala).