Suzuki 2000 Grand Vitara SQ625 Service Manual page 96

6-92 ENGINE DIAGNOSIS (G16 / J20 ENGINES)
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool and warm up
engine completely.
3) Run engine at idle speed for 1 min.
4) Check DTC and pending DTC by using scan tool.
TROUBLESHOOTING (P0505)
STEP
1 Was "ENGINE DIAG. FLOW TABLE" performed?
2 Idle Speed Check:
1) Check engine idle speed referring to
"Idle Speed/Idle Air Control Duty Inspection"
in Section 6E1.
Is engine idle speed within specification?
3 IAC Valve Check:
1) Check IAC valve referring to "IAC Valve
Inspection" in Section 6E1.
Is check result as specified?
4 IAC Valve Circuit Check:
1) With ignition switch OFF, disconnect ECM
(PCM) couplers.
2) Check for proper connection to IAC valve
at C51-2-3, C51-2-12, C51-2-11 and
C51-2-10 terminals.
3) If OK, check resistance between C51-2-3
and C51-2-12, C51-2-10 and C51-2-11.
Is each resistance 70 – 86 W?
5 IAC Valve Power Supply Voltage Check:
1) Connect ECM (PCM) couplers.
2) With ignition switch OFF, disconnect C29
coupler of IAC valve.
3) With ignition switch ON, check voltage
between C29-2 and ground, C29-5 and ground.
Is each voltage 10 – 14 V?
6 Was idle speed higher than specification in Step 2?
ACTION YES
Go to Step 2.
Intermittent trouble or
faulty ECM (PCM).
Check for intermittent
referring to "Intermit-
tent and Poor
Connection" in
Section 0A.
Go to Step 6.
Go to Step 5.
IAC valve or ECM
(PCM) malfunction.
Check abnormal air
inhaling from intake
manifold, throttle
body, PCV valve and
EVAP canister purge
control system.
NO
Go to "ENGINE DIAG.
FLOW TABLE".
Go to Step 3.
Go to Step 4.
"Lg/B", "V/B", "Gr/Bl"
or "V/Y" wire open or
short.
If wire and connections
are OK, replace IAC
valve.
Open "Bl/B" wire.
Check parts or system
which can cause engine
low idle.
– Air inhaling from
between throttle body
and MAF sensor.
– EGR valve malfunc-
tion (leakage from
valve seat)
– Accessary engine load
– Clog of idle air passage
– Engine mechanical
– Engine overheat
– Etc.