Suzuki DF150 Service Manual page 100

ENGINE CONTROL SYSTEM 3-41
NOTE 1: MAP sensor
These conditions will be caused by IAC valve failure or incorrect
O-ring
by-pass air screw adjustment. If IAC valve is always closed or
by-pass air is too low, the ECM controls the IAC valve duty to
increase to maintain the idling/trolling speed specified.
NOTE 2:
This condition will be caused by clogged pressure detect pas- Passage
sage in intake manifold.