Heated Steering Wheel Module (HSWM)
The Heated Steering Wheel Module (HSWM) controls the steering wheel heating function and the control module is located behind the dashboard just above the OBD socket. The control module regulates the temperature in the heating element around 32 °C using a PWM supply. The heating element is located inside the grip of the steering wheel. A temperature sensor in the form of a thermistor (NTC resistor) transmits information about the heating element temperature via the Steering Wheel Module (SWM) on a private LIN bus to the Heated Steering Wheel Module (HSWM).
The control module is supplied via a relay in the fusebox in the passenger compartment (V70, XC70, S80, S80L) or via a relay in the Central Electronic Module (CEM) (All 60 models). Activation is via a dedicated switch on the Climate Control Module (CCM).
The Heated Steering Wheel Module (HSWM) can be diagnosed via the Central Electronic Module (CEM).