Topology of the Auxiliary Heater

Topology Of The Auxiliary Heater

The auxiliary heater is connected to the CAN MMI. The following diagram shows which control units supply data or information for auxiliary heating operation.







Task distribution for auxiliary heater

The following list provides an overview of the (main) tasks of the individual control units during auxiliary heater operation.

Instrument cluster (master)
- Operation/activation of the auxiliary heater via the multi-function display
- Programming a timer (timer in the gateway)
- Signal output for activation of the auxiliary heater (check of switch-on conditions is necessary)
- Output of messages and warnings

Auxiliary heater (control unit)

NOTE: The 3/2 directional-control valve is controlled directly by the auxiliary heater control unit in the Cayenne.

- Input for switch-on and switch-off signals from the remote control and forwarding via CAN MMI to the instrument cluster (master)
- Activation of the auxiliary heating function (request from master [instrument cluster] is necessary for this)
- Control of internal heating processes including fuel metering (e.g. activation of the metering pump) for heating operation

Operating and air-conditioning unit (front)
- Forwarding of the request or deactivation signal from the auxiliary heater button in the center console
- Controlled warm air distribution (warming-up and defrosting)
- Control of the actuators (e.g. passenger-compartment fan, servo motors and water pump)

Gateway
- Signal for activation of the auxiliary heater after check of switch-on conditions (e.g. energy management)
- Timer
- Signal routing