Suzuki Ignis Service Manual page 3277

6-76 ENGINE GENERAL INFORMATION AND DIAGNOSIS
TROUBLESHOOTING
Step
1 Was "Engine and Emission Control System
Check" performed?
2 IAT sensor and its circuit check.
1) Connect scan tool with ignition switch
turned OFF.
2) Turn ON ignition switch.
3) Check intake air temp. displayed on scan
tool.
Is 165°C (329°F) indicated?
3 Check ECM voltage.
1) Disconnect connector from IAT sensor with
ignition switch turned OFF.
2) Check for proper connection to IAT sensor
at "LT GRN/BLK" and "ORN" wire terminals.
3) If OK, then turn ON ignition switch, check
voltage between "LT GRN/BLK" wire termi-
nal of IAT sensor connector and vehicle
body ground. See Fig. 1.
Is voltage about 4 – 6 V?
4 Check IAT circuit insulation.
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Measure resistance between "LT GRN/
BLK" wire terminal of IAT sensor connector
and body ground.
Is resistance infinity?
5 Check IAT short circuit.
1) Turn ON ignition switch.
2) Check voltage between "LT GRN/BLK" wire
terminal of IAT sensor connector and vehi-
cle body ground.
Is voltage about 0 V?
6 Check IAT sensor according to "Mass air flow
(MAF) and intake air temperature (IAT) sensor
inspection" in Section 6E1.
Is it in good condition?
[A]
1
Action
V
2
Yes
Go to Step 2.
Go to Step 3.
Go to Step 6.
Go to Step 5.
Go to Step 6.
Substitute a known-good
ECM and recheck.
[A]: Fig.1 for Step 3
1. Disconnected MAF and IAT sensor connector
2. Engine ground
No
Go to "Engine and Emis-
sion Control System
Check" in this section.
Intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection" in
Section 0A.
Go to Step 4.
"LT GRN/BLK" wire
shorted to ground circuit.
If wire are OK, substitute
a known-good ECM and
recheck.
"LT GRN/BLK" wire
shorted to other circuits.
If wire are OK, substitute
a known-good ECM and
recheck.
Replace MAF and IAT
sensor.