Porsche Cayenne Owner's Manual page 85

Parking heater faults
Initial start-up following period of non-
utilization
If you have not used the parking heater for several
weeks, the system may require the parking heater
to be switched on several times before it actually
"starts up".
f Please take a break of approximately
5 minutes between each individual switch-on
attempt.
Requirement for initial start-up of the
parking heater:
– Cold engine.
Have the parking heater checked by an authorized
Porsche dealer in the following cases:
– If the parking heater fails to "start-up" after the
3rd switch-on attempt.
– In the event of faults in the parking heater, no
function symbol appears on the display – only
the remaining running time is shown.
The display flashes on briefly and then goes
completely dark.
– In the event of a serious accident, the parking
heater switches off automatically for safety
reasons.
The parking heater is not ready for operation.
– If the temperature rises, the overheating
protection switches the parking heater off
automatically. The parking heater is not ready
for operation.
– The parking heater is switched off automati-
cally if the voltage is too low. The parking
heater is temporarily unavailable.
Air Conditioning, Parking Heater and Heated Rear Window
85