Suzuki TU250X Service Manual page 156

Step 3
1) Turn the ignition switch OFF.
2) Remove the IAP sensor. (4-68)
3) Connect the vacuum pump gauge to the vacuum port of the
IAP sensor.
Arrange 3 new 1.5 V batteries in series 1 (check that total -
voltage is 4.5 – 5.0 V) and connect - terminal to the ground -
terminal 2 and + terminal to the VCC terminal 3.
4) Check the voltage between Vout 4 and ground. Also, check
if voltage reduces when vacuum is applied by using vacuum
pump gauge. (Below)
 09917-47011: Vacuum pump gauge set
09900-25008: Multi circuit tester set
 Tester knob indication: Voltage ()
Is the voltage OK?
• W/Bl, R or B/Br wire open or shorted to ground,
or poor 7, A or T connection
• If wire and connection are OK, intermittent trou-
ble or faulty ECM.
YES
• Recheck each terminal and wire harness for
open circuit and poor connection.
• Replace the ECM with a known good one, and
inspect it again.
If check result is not satisfactory, replace the IAP
NO
sensor with a new one.
Output voltage (VCC voltage 4.5 – 5.0 V, ambient temp. 20 –
30 °C, 68 – 86 °F)
Atmospheric pressure
(mmHg)
760
707
634
567
526
Output voltage
kPa (V)
100 Approx. 2.86
94 Approx. 2.70
85 Approx. 2.45
76 Approx. 2.21
70 Approx. 2.05
FI SYSTEM DIAGNOSIS 4-35
3
3
ECM coupler (Harness side)
V