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 Descriptors
DTC B2425 04: Left Seat Heater Cushion Circuit OpenDTC 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 |
|---|---|---|---|---|
Left rear heated seat back element supply voltage | B2508 02 | B1935 0C, B1935 0D | B2345 00, B2508 01 | B1935 0B, B1935 0E |
Left rear heated seat back element control | B2345 00, B2508 02 | B1935 0C, B1935 0D | B2345 00, B2508 01 | B1935 0B, B1935 0E |
Left rear 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 |
Left rear heated seat back temperature sensor low reference | -- | B1935 04, B1935 1F, B2435 0D | -- | B2345 13, B2345 42, B2345 4B |
Left rear heated seat cushion element supply voltage | B2508 02 | B2425 0C, B2425 0D | B2345 00, B2508 01 | B2425 0B, B2425 0E |
Left rear heated seat cushion element control | B2345 00, B2508 02 | B2425 0C, B2425 0D | B2345 00, B2508 01 | B2425 0B, B2425 0E |
Left rear 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 |
Left rear heated seat cushion temperature sensor low reference | -- | B1925 05, B2425 04, B2425 1F | -- | B2345 13, B2345 42, B2345 4B |
Right rear heated seat back element supply voltage | B2508 02 | B2180 0C, B2180 0D | B2345 00, B2508 01 | B2180 0B, B2180 0E |
Right rear heated seat back element control | B2345 00, B2508 02 | B2180 0C, B2180 0D | B2345 00, B2508 01 | B2180 0B, B2180 0E |
Right rear 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 |
Right rear heated seat back temperature sensor low reference | -- | B2180 04, B2180 1F, B2440 05 | -- | B2345 13, B2345 42, B2345 4B |
Right rear heated seat cushion element supply voltage | B2508 02 | B2430 0C, B2430 0D | B2345 00, B2508 01 | B2430 0B, B2430 0E |
Right rear heated seat cushion element control | B2345 00, B2508 02 | B2430 0C, B2430 0D | B2345 00, B2508 01 | B2430 0B, B2430 0E |
Right rear 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 |
Right rear 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 rear passenger heated seats are controlled by the rear heated seat module (RHSM). 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 module 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 temperatures 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 heated seat system must be active.
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 fro 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 RHSM calculates that the heating element resistance is below the minimum resistance value of 5.4 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 RHSM calculates that the heating element resistance is above the maximum resistance value of 13.2 ohms.
B2425 1F, B2430 1F
The temperature sensor voltage is erratic, sudden change, or intermittent.
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. |
Reference Information
Schematic Reference
Connector End View Reference
Power Seat Connector End Views
Electrical Information Reference
Scan Tool Reference
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 RHSM.
- Test for less than 13.2 ohms between the supply voltage terminal 3 and the control circuit terminal 5.
- Ignition OFF, disconnect the C2, C4 harness connectors at the RHSM.
- Test for 1.4K-300K ohms between the signal circuit terminal 9 C4 and the low reference circuit terminal 6 C2.
- Ignition OFF, connect the C1, C2, C4 harness connectors at the RHSM.
- 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 all circuits test normal, replace the RHSM.
| ⇒ | 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. |
| ⇒ | 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 tests normal, replace the seat cushion temperature sensor. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the RHSM. |
B2430 0A, B2430 0B, B2430 0C, B2430 0D, B2430 0E, B2430 04, or B2430 1F
- Ignition OFF, disconnect the C1 harness connector at the RHSM.
- Test for less than 13.2 ohms between the supply voltage circuit terminal 6 and the control circuit terminal 2.
- Ignition OFF, disconnect the C2, C4 harness connectors at the RHSM.
- Test for 1.4K-300K ohms between the signal circuit terminal 20 C4 and the low reference circuit terminal 8 C2.
- Ignition OFF, connect the C1, C2, C4 harness connectors at the RHSM.
- 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 all circuits test normal, replace the RHSM.
| ⇒ | 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. |
| ⇒ | 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. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the RHSM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for RHSM replacement, setup, and programming |
