HYOSUNG MS3 125, Sercie Manual, Page: 120 / 257

4-23 FI SYSTEM DIAGNOSIS
Output voltage
(Input voltage 5 V, ambient temp. 25 °C, 77 °F)
ALTITUDE
(Reference)
(ft)(m) (mmHg) kPa (V)
0
2 000
0
610
760
707
100
94
2 001
5 000
611
1 524
707
634
94
85
5 001
8 000
1 525
2 438
634
567
85
76
8 001
10 000
2 439
3 048
567
526
76
70
ATMOSPHERIC
PRESSURE
OUTPUT
VOLTAGE
Approx.
4.0 ~ 4.3
Approx.
3.6 ~ 4.0
Approx.
3.3 ~ 3.6
Approx.
3.0 ~ 3.3
◈
Step 2
1) Connect the IAP sensor coupler.
2) Insert the needle pointed probes to the lead wire
coupler.
3) Start the engine at idle speed.
4) Measure the IAP sensor output voltage at the wire
side coupler (between BL and BW wires).
IAP sensor
output voltage
Approx. 4.0 ~ 4.2 V
when ignition switch “ ” (ON)
( � BL - � BW )
Is the voltage OK?
YES
NO
●
OB, BL or BW wire open or
shorted to ground, or poor
� , �
or
⑤
connection.
●
If wire and connection are OK,
intermittent trouble or faulty ECU.
●
Recheck each terminal and wire
harness for open circuit and poor
connection.
If check result is not satisfactory,
replace IAP sensor with a new one.
Tester knob indication : Voltage ( )
ECU Coupler
�
⑤
�