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. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
B+ MSM Terminal 5 X3 | 1, 2, B2425 0D, B2430 0D | 1, 2, B2425 0D, B2430 0D | -- | -- |
Driver Heated Seat Element Supply Voltage | B2508 02 | B2425 0D | B2508 01 | B2425 0E |
Driver Heated Seat Element Control | B2508 02 | B2425 0D | B2508 01 | B2425 0E |
Driver Heated Seat Temperature Sensor Signal | B1925 02 | B1925 05 | B1925 05 | B2345 13, B2345 42, B2345 4B |
Driver Heated Seat Temperature Sensor Low Reference | -- | B1925 05 | -- | B2345 13, B2345 42, B2345 4B |
Passenger Heated Seat Element Supply Voltage | B2508 02 | B2430 0D | B2508 01 | B2430 0E |
Passenger Heated Seat Element Control | B2508 02 | B2430 0D | B2508 01 | B2430 0E |
Passenger Heated Seat Temperature Sensor Signal | B2170 02 | B2170 05 | B2170 05 | B2345 13, B2345 42, B2345 4B |
Passenger Heated Seat Temperature Sensor Low Reference | -- | B2170 05 | -- | B2345 13, B2345 42, B2345 4B |
1. Power seats inoperative 2. Heated seats inoperative | ||||
Circuit/System Description
The driver and passenger heated seats are controlled by separate heated seat switches located in the radio/HVAC control panel. When a heated seat switch is pressed, a serial data message is sent to the radio. The radio then serves as a gateway to transmit the serial data message to the memory seat module (MSM) indicating the heated seat command. In response to this signal, the MSM then applies or removes battery voltage through the element supply voltage circuit of the seat heating elements. The MSM then sends a serial data message back to the radio to gateway the information to the radio/HVAC control panel to either illuminate or turn off the appropriate temperature indicator.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Heated/Vented Seat Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the X3 harness connector at the MSM.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 5 and ground.
- Ignition OFF, connect the X3 harness connector at the MSM.
- Ignition ON, observe the scan tool Radio Driver Heated Seat Sw. parameter while pressing the driver HEATED seat switch. The readings should change between Inactive and Active.
- Observe the scan tool Radio Pass. Heated Seat Sw. parameter while pressing the passenger HEATED seat switch. The readings should change between Inactive and Active.
- If the scan tool readings are normal, there are no DTCs set, and the driver and/or passenger heated seat is inoperative, replace the MSM.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If not the specified value, replace the radio/HVAC control panel. |
| ⇒ | If not the specified value, replace the radio/HVAC control panel. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for MSM replacement, setup, and programming |
