Suzuki Engine 2002 GRAND VITARA SQ625, Service Manual

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ENGINE AND EMISSION CONTROL SYSTEM (H25 ENGINE) 6E2-21
viii) Remove service wire from diagnosis connector.
ix) Check that specified engine idle speed is obtained with A/
C ON if vehicle is equipped with A/C.
If not, check A/C ON signal circuit and idle air control sys-
tem.
Idle mixture inspection/adjustment (vehicle without
heated oxygen sensor)
All vehicles not equipped with heated oxygen sensor are shipped
with their CO% factory adjusted as follows.
Engine idle mixture (CO%) at specified idle speed
0.8 – 1.3%
Idle mixture adjustment should never be changed from the origi-
nal factory setting. However, if during diagnosis, the check indi-
cates idle mixture to be the cause of a driver performance
complaint or emission failure, the idle mixture can be adjusted
using the following procedures.
1) Check idle speed according to “Idle Speed/Idle Air Control
Duty Inspection” in this section.
2) Using exhaust gas tester, check that idle mixture CO% is
within above specification. If it is out of specification, adjust it
to specification by turning resistor knob (1).
3) If idle mixture has been adjusted, confirm that idle speed/IAC
duty is within specification.
NOTE:
For this inspection and adjustment, exhaust gas tester
(CO meter) and engine tachometer are necessary.