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EDK THROTTLE POSITION FEEDBACK SIGNALS
The EDK throttle plate position is monitored by two integrated potentiometers. The poten-
tiometers provide DC voltage feedback signals as input to the ME 7.2 for throttle and idle
control functions.
Potentiometer signal 1 is the primary signal, Potentiometer sig-
nal 2 is used as a plausibility cross-check through the total
range of throttle plate movement.
EDK FEEDBACK
SIGNAL MONITORING & FAILSAFE OPERATION:
• If plausibility errors are detected between Pot 1 and Pot 2, ME 7.2 will calculate the
inducted engine air mass (from HFM signal) and only utilize the potentiometer signal that
closely matches the detected intake air mass.
- The ME 7.2 uses the air mass signalling as a “virtual potentiometer” (pot 3) for a
comparative source to provide failsafe operation.
- If ME 7.2 cannot calculate a plausible conclusion from the monitored pots (1 or 2
and virtual 3) the EDK motor is switched off and fuel injection cut out is activated
(no failsafe operation possible).
• The EDK is continuously monitored during all phases of engine operation. It is also
briefly activated when KL 15 is initially switched on as a “pre-flight check” to verify it’s
mechanical integrity (no binding, appropriate return spring tension) by monitoring the
motor control amperage and the reaction speed of the EDK feedback potentiometers.
If faults are detected the EDK motor is switched off and fuel injection cut off is activat-
ed (no failsafe operation possible). The engine does however continue to run extreme-
ly rough at idle speed.
