Suzuki WagonR+ RB310 Service Manual page 643

6-2-72 ENGINE GENERAL INFORMATION AND DIAGNOSIS (M13 ENGINE)
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" and "BRN/WHT" wire terminals.
3) If OK, then turn ON ignition switch, check
voltage between "LT GRN" wire terminal 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" 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" wire termi-
nal of IAT sensor connector and vehicle 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 6E2.
Is it in good condition?
[A]
2
Action
1
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
Inspection" in
Section 0A.
Go to Step 4.
"LT GRN" wire shorted to
ground circuit.
If wire are OK, substitute
a known-good ECM and
recheck.
"LT GRN" wire shorted to
other circuits.
If wire are OK, substitute
a known-good ECM and
recheck.
Replace MAF and IAT
sensor.