C21" Iat Sensor Circuit Malfunction - HYOSUNG AQUILA 650 FI Service Manual

4-1-27 FI SYSTEM DIAGNOSIS

"C21" IAT SENSOR CIRCUIT MALFUNCTION

DETECTED CONDITION
Output voltage is out of the specified range.
0.2 V � Sensor voltage � 4.6 V
▣ ▣ INSPECTION
◈ Step 1
1) Remove the fuel tank.
2) Turn the ignition switch "OFF" position.
3) Check the IAT sensor coupler for loose or poor
contacts.
If OK, then measure the IAT sensor voltage at the
wire side coupler.
4) Disconnect the coupler and turn the ignition switch
"ON" position.
5) Measure the voltage between GW wire terminal
and ground.
6) If OK, then measure the voltage between GW wire
terminal and GR wire terminal.
IAT sensor 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 GW
wire or GR wire.
4.5 ~ 5.5 V
( � GW - �
Ground )
( � GW - � GR )
)
POSSIBLE CAUSE
● IAT sensor circuit open or short.
● IAT sensor malfunction.
● ECU malfunction.
GR
GW
38