The 12V controller is the main Electronic Control Unit (ECU) for the Tesla Roadster HVAC system. It signals the 400V controller, based on control settings and Vehicle Management System (VMS) requests, to control the desired level of heating or cooling.
This module communicates with the VMS via the CAN bus and also monitors faults. It is fitted at the front of the center console on the RH side.
| Module role | Main 12V HVAC ECU; commands the 400V controller to achieve requested heating/cooling |
| Vehicle communications | CAN bus communication with VMS; monitors and reports faults |
| Key inputs | Air distribution, fan request, recirculation request, VMS load shedding |
| Sensors / statuses monitored | Ambient, evaporator inlet, cabin outlet, battery coolant temp, refrigerant pressure, A/C & heater switch status, temperature dial setting |
| Installation location | Front of the center console on the RH side |
Service notes: Because HVAC complaints can be caused by inputs/sensors/wiring as well as the ECU itself, we recommend documenting fault behavior and any recent work before removal. Include photos of connectors and any fault notes to speed triage.
