Suzuki SY413 Service Manual page 2761

6-2-44 ENGINE GENERAL INFORMATION AND DIAGNOSIS (J18 ENGINE WITH WU TWC)
TROUBLESHOOTING
STEP
1 Was "ENGINE DIAG. FLOW TABLE" performed?
2 Check IAT Sensor and Its Circuit.
1) Connect scan tool with ignition switch OFF.
2) Turn ignition switch ON.
3) Check intake air temp. displayed on scan tool.
Is – 40_C (– 40_F) or 205_C (401_F) indicated?
3 Check Wire Harness.
1) Disconnect IAT sensor connector with ignition
switch OFF.
2) Check for proper connection to IAT sensor at
"Gr/R" and "Or" wire terminals.
3) If OK, then with ignition switch ON, is voltage
applied to "Gr/R" wire terminal about 4 – 6 V?
See Fig. 1.
4 Does scan tool indicate –40_C (–40_F) at Step 2?
5 IAT sensor circuit check:
1) Disconnect IAT sensor connector.
2) Check intake air temp. displayed on scan tool.
Is – 40_C (– 40_F) indicated?
6 Check Wire Harness.
1) Using service wire, connect IAT sensor connec-
tor terminals.
2) Turn ignition switch ON and check intake air
temp. displayed on scan tool. See Fig. 2.
Is 205_C (401_F) indicated?
Fig.1 for Step 3
ACTION
1. IAT sensor coupler disconnected
2. Engine ground
YES
Go to Step 2.
Go to Step 3.
Go to Step 5.
Go to Step 6.
Replace IAT sensor.
Replace IAT sensor.
Fig.2 for Step 6
1. IAT sensor coupler disconnected
2. Service wire
NO
Go to "ENGINE DIAG.
FLOW TABLE".
Intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection" in
Section 0A.
"Gr/R" wire open or
shorted to power, or
poor C20-16 connec-
tion.
If wire and connection
are OK, substitute a
known-good ECM and
recheck.
Go to Step 5.
"Gr/R" wire shorted to
ground.
If wire is OK, substitute
a known-good ECM and
recheck.
"Or" wire open or poor
C20-27 connection.
If wire and connection
are OK, substitute a
known-good ECM and
recheck.