Suzuki 2000 Grand Vitara SQ416, Service Manual

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YH4
GRAND
VITARA
6-46 ENGINE DIAGNOSIS (G16 / J20 ENGINES)
TROUBLESHOOTING
STEP ACTION YES NO
1 Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE
DIAG. FLOW
TABLE”.
2 MAF sensor Check:
1) Connect scan tool to DLC with ignition switch OFF.
2) Start engine and check MAF value displayed on scan
tool. (Refer to “Scan Tool Data” for normal value.)
Is normal value indicated?
Intermittent trouble.
Check for intermit-
tent referring to
“Intermittent and
Poor Connection” in
Section 0A. Go to Step 3.
3 MAF sensor power supply Check:
1) With ignition switch OFF, disconnect MAF sensor
coupler.
2) With ignition switch ON, check voltage between C32-3
of MAF sensor coupler and ground.
Is voltage 10 – 14 V?
Go to Step 4. Faulty “Bl / B” wire.
4 MAF sensor output voltage Check:
1) With ignition switch OFF, connect MAF sensor
coupler.
2) Remove ECM (PCM) cover.
3) With ignition switch ON leaving engine OFF, check
voltage between C51-3-10 and C51-3-5 terminal.
Is voltage 1.0 – 1.6 V?
Poor C51-3-10
connection.
If OK, substitute
a known-good
ECM (PCM) and
recheck. Faulty “V / W” wire.
Poor C32 coupler
terminal connection.
If wire and connec-
tion are OK, substi-
tute a known-good
MAF sensor and
recheck.