C17 " " O O R R " " C18 " " Iap Sensor Circuit Malfunction - HYOSUNG AQUILA 650 FI Service Manual

4-1-25 FI SYSTEM DIAGNOSIS
"C17" or "C18" IAP SENSOR CIRCUIT MALFUNCTION
DETECTED CONDITION
IAP sensor voltage is out of the specified range.
0.2 V � Sensor voltage � 4.8 V
NOTE :
Note that atmospheric pressure varies depending on
weather conditions as well as altitude.
Take that into consideration when inspecting voltage.
▣ ▣ INSPECTION
◈ Step 1
1) Remove the fuel tank.
2) Turn the ignition switch "OFF" position.
3) Check the IAP sensor NO.1 coupler ①
coupler ② for loose or poor contacts. If OK, then
measure the IAP sensor input voltage.
4) Disconnect the IAP sensor coupler NO.1 ③
NO.2 ④ .
5) Turn the ignition switch "ON" position.
6) Measure the voltage at the OB wire and ground. If
OK, then measure the voltage at the OB wire and
GR wire.
IAP sensor input
voltage
Tester knob indication : Voltage (
Is the voltage OK?
YES Go to Step 2.
● Loose or poor contacts on the
ECU coupler.
NO
● Open or short circuit in the OB
wire or GR wire.
and NO.2
and
4.5 ~ 5.5 V
( � OB - �
Ground )
( � OB - �
GR )
)
POSSIBLE CAUSE
● Clogged vacuum passage between throttle body
and IAP sensor.
● Air being drawn from vacuum passage between
throttle body and IAP sensor.
● IAP sensor circuit open or shorted to ground.
● IAP sensor malfunction.
● ECU malfunction.
①
36
②
③
④