L322 Range Rover System Description and Operation
AIR CONDITIONING
82-48
DESCRIPTION AND OPERATION
At a programmed parked heating/ventilation start time, or when parked heating/ventilation is selected on using the
MID/MFD, the instrument pack outputs:
l
A parked heating/ventilation request to the MID/MFD on the I bus
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A parked heating/ventilation request to the ATC ECU and the Body Control Unit (BCU) on the K bus
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Ambient and engine temperatures to the ATC ECU and BCU on the K bus.
On receipt of the messages:
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The red LED on the MID/MFD panel flashes at 2 Hz to indicate that parked heating/ventilation is active
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If the ambient temperature is less than 5
°
C (41
°
F), the BCU activates the door mirror heaters for 3 minutes
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If parked heating is activated, the ATC ECU:
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Energises the changeover valve
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Sends a K bus message to activate the FBH
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Operates the blower at speed 1
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Opens the windscreen distribution flaps in the heater assembly and closes the face and footwell flaps.
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If parked ventilation is activated, the ATC ECU:
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Operates the blower at speed 1
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Opens the face level distribution flaps in the heater assembly and closes the windscreen and footwell flaps.
When parked heating/ventilation is selected off, or after 30 minutes has elapsed, the instrument pack sends parked
heating/ventilation off messages on the I and K buses. On receipt of the messages:
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The MID/MFD switches off the LED
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If parked heating is active, the ATC ECU:
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Sends a K bus message to de-activate the FBH
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Switches off the blower
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Returns the distribution flaps to the previous settings
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After 3 minutes, de-energises the changeover valve.
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If parked ventilation is active, the ATC ECU:
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Switches off the blower
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Returns the distribution flaps to the previous settings.
Remotely Selected Parked Heating/Ventilation
When parked heating/ventilation is selected on with the remote handset, the request is received by the FBH receiver
via the TV antenna and TV receiver. The FBH receiver relays the request as a hardwired signal to the FBH ECU. On
receipt of the request, the FBH ECU sends the request to the ATC ECU and the instrument pack on the K bus. Parked
heating/ventilation then operates as detailed above.
