Rotax 914 F Installation Manual page 77

Besides the throttle position, overspeeding of the engine and too high intake air
temperature have an effect on the nominal boost pressure.
If one of the stated factors exceeds the specified limits, the boost pressure is
automatically reduced, thus protecting the engine against overload.
The TCU (Turbo Control Unit) is furnished additionally with output connections for an
external "red" boost lamp and an "orange" caution lamp for indication of function of
the TCU.
When switching on the voltage supply, the two lamps are automatically subject to a
function test. Both lamps illuminate for 1 - 2 seconds, then they extinguish. If they do
not, a check as per Maintenance Manual is necessary.
WARNING: The engine must not be taken into operation before having corrected
Orange caution lamp:
The non-illuminated orange caution lamp signals that TCU is ready for operation.
If the lamp is blinking, this indicates a malfunction of the TCU or its periphery.
Red boost lamp:
Exceeding of the admissible boost pressure will activate the red boost lamp, being
continuously illuminated.
The TCU registers the time of full throttle operation (boost pressure). Full throttle
operation for longer than 5 minutes will make the red boost lamp blinking
Modification-No.
- 0 -
the cause of deficiency.
Reference Install Date
1996 05 10
914 F
Page
77