• | 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 |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
B+ MSM Terminal 5 X3 | 1, 2, B1935 0C, B1935 0D, B2180 0C, B2180 0D, B2425 0C, B2425 0D, B2430 0C, B2430 0D | 1, 2, B1935 0C, B1935 0D, B2180 0C, B2180 0D, B2425 0C, B2425 0D, B2430 0C, B2430 0D | -- | -- |
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 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 |
1. Power seat inoperative 2. Heated seat inoperative |
The driver and front passenger seat heating elements are controlled by a common high current relay internal to the memory seat module (MSM) and the low side by individual element control circuits. The MSM connects the heated seat heater element supply voltage circuits for both seats to a common reference point. This reference point is biased to approximately 2.0 volts. Before the MSM will allow heated seat operation, it checks to see if this reference voltage is shorted to ground or battery voltage. Once the module verifies that it is not closing to a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.
The MSM must be powered.
After a heated seat is activated, the MSM detects a shorted circuit on the seat heating element supply voltage circuit or control circuit.
Any of the temperature sensor input remains below 1.5 volts for a seat back or 0.95 volts for a seat cushion more than 1 second.
This DTC will set if the module calibration is not programmed.
This DTC will set if the module calibration is out of range.
The heated seat functions for both front seats will be disabled.
• | 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. |
Heated/Cooled Seat Connector End Views
⇒ | If not the specified value, test the supply voltage circuit and the control circuits listed below for a short to ground: |
• | Driver seat cushion and seat back terminal 14 X1 |
• | Driver seat cushion element terminal 11 X1 |
• | Driver seat back element terminal 1 X1 |
⇒ | If not the specified value, test the supply voltage circuit and the control circuits listed below for a short to ground: |
• | Passenger seat cushion and seat back terminal 6 X1 |
• | Passenger seat cushion element terminal 14 X4 |
• | Passenger seat back element terminal 4 X1 |
⇒ | If the test lamp illuminates, test the supply voltage circuit and the control circuits listed below for a short to voltage: |
• | Driver seat cushion and seat back terminal 14 X1 |
• | Driver seat cushion element terminal 11 X1 |
• | Driver seat back element terminal 1 X1 |
⇒ | If the test lamp illuminates, test the supply voltage circuit and the control circuits listed below for a short to voltage: |
• | Passenger seat cushion and seat back terminal 6 X1 |
• | Passenger seat cushion element terminal 14 X4 |
• | Passenger seat back element terminal 4 X1 |
• | Driver seat cushion terminal 1 X5 and terminal 3 X2 |
• | Passenger seat cushion terminal 2 X5 and terminal 6 X2 |
⇒ | If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat cushion heater element/temperature sensor. |
• | Driver seat back terminal 4 X5 and terminal 2 X2 |
• | Passenger seat back terminal 3 X5 and terminal 5 X2 |
⇒ | If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat back heater element/temperature sensor. |
If either DTC is set, replace the MSM.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for the MSM replacement, setup, and programming |