Suzuki Engine 2002 GRAND VITARA SQ625, Service Manual

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ENGINE GENERAL INFORMATION AND DIAGNOSIS (G16/J20 ENGINES) 6-125
3 Check IAC valve referring to “IAC Valve
Inspection” in Section 6E1.
Is check result as specified? Go to Step 4. IAC valve malfunction, “BLU/
BLK”, “LT GRN/BLK”, “PPL/
BLK”, “GRY/BLU” or “PPL/
YEL” wire open or short or
poor coupler connection.
If all above are OK, substi-
tute a known-good ECM
(PCM) and recheck.
4 Was idle speed within specification in
Step 1? Check for following :
• Vacuum leaks
• Air inhaling
• EVAP canister purge con-
trol system
• Accessory engine load
• Stuck of PCV valve
• Clog of idle air passage
• MAF sensor
• TP sensor
• ECT sensor
• EGR valve malfunction
(leakage from valve seat)
• A/C signal
• Transmission range switch
signal
Go to Step 5.
5 Was idle speed higher than specification
in Step 1? Go to Step 6. Go to Step 9.
6 Check A/C (input) signal circuit referring
to Step 1 of Table B-5 or Table B-6 A/C, if
equipped. (A/C signal can be also
checked by using SUZUKI scan tool.)
Is it in good condition? Go to Step 7. A/C signal circuit open or
short, or A/C system mal-
function.
7 Check ABS signal circuit for voltage if
equipped.
1) Turn ignition switch ON.
2) Check voltage between E61-30 termi-
nal of ECM (PCM) connector con-
nected and body ground.
Is voltage 10 – 14 V?
Go to step 8. ABS signal circuit shorted to
ground or ABS malfunction.
8 Was IAC duty less than about 2% in Step
1 of this table? Check abnormal air inhaling
from intake manifold, throttle
body, PCV valve and EVAP
canister purge control sys-
tem. Check TP sensor (closed
throttle position) and ECT
sensor for performance.
If sensors are OK, substitute
a known-good ECM (PCM)
and recheck.
9 Check transmission range switch signal
referring to “Inspection of ECM (PCM)
and its Circuit” in this section.
Is check result satisfactory? Go to Step 10. Transmission range switch
malfunction or its circuits
open or short.
Step Action Yes No