21" Iat Sensor Circuit Malfunction - Suzuki RM-z450 Owner's Service Manual

"21" IAT SENSOR CIRCUIT MALFUNCTION

DETECTED CONDITION
Output voltage is not within the following range.
0.2 V Sensor voltage < 4.8 V
IAT sensor
When using the multi-circuit tester, do not strongly touch the terminal of the ECM coupler with
a needle pointed tester probe to prevent the terminal damage or terminal bend.
INSPECTION
Step 1
1) Stop the engine.
2) Remove the seat and fuel tank rubber band. ("5-2)
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 IAT sensor coupler.
5) Connect a 12 volts battery using the battery lead wire to ser-
vice coupler. ("12-22)
6) Measure the voltage between Dg wire terminal A and
ground.
7) If OK, then measure the voltage between Dg wire terminal A
and B/Br wire terminal B.
# IAT sensor input voltage: 4.5 – 5.5 V
! 09900-25008: Multi-circuit tester set
36890-28H00: Battery lead wire (option)
% Tester knob indication: Voltage (&)
Is the voltage OK?
YES Go to Step 2.
• Loose or poor contacts on the ECM coupler
(terminal N or O).
NO
• Open or short circuit in the Dg wire or B/Br wire.
• IAT sensor circuit open or short.
• IAT sensor malfunction.
• ECM malfunction.
Dg
B/Br
CAUTION
(+ Dg – - Ground)
(+ Dg – - B/Br)
FI SYSTEM DIAGNOSIS
POSSIBLE CAUSE
ECM
IAT
E2
1
1
V
12-34