Suzuki Grand Vitara 2011 Manual page 317

Troubleshooting
NOTE
• Before performed troubleshooting, be sure to read the "Precautions of ECM Circuit Inspection: For
Petrol Engine Model".
• When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors referring to "Inspection of ECM and Its Circuits: For
Petrol Engine Model".
Step
1 Fuel injector check for operating sound
1) Using sound scope, check each injector for operating
sound at engine cranking.
Do all 4 injector make operating sound?
2 Fuel injector resistance check
1) Disconnect connectors from fuel injectors with ignition
switch turned OFF.
2) Check for proper connection to fuel injector at each
terminals.
3) If OK, check all 4 fuel injectors for resistance referring to
"Fuel Injector On-Vehicle Inspection: For Petrol Engine
Model in Section 1G".
Are all injectors in good condition?
3 Fuel injector insulation resistance check
1) Check that there is insulation between each fuel injector
terminal and engine ground.
Is there insulation?
4 Fuel injector power supply check
1) Measure voltage between each "BLU/BLK" wire terminal
of fuel injector connector and engine ground with ignition
switch turned ON.
Is voltage 10 – 14 V?
5 Wire circuit check
1) Turn OFF ignition switch.
2) Disconnect connectors from ECM.
3) Measure resistance between each "PNK", "PNK/BLK",
"PNK/GRN", "PNK/BLU" wire terminal of fuel injector
connector and vehicle body ground.
Is resistance infinity?
6 Wire circuit check
1) Measure voltage between each "PNK", "PNK/BLK",
"PNK/GRN", "PNK/BLU" wire terminal of fuel injector
connector and vehicle body ground with ignition switch
turned ON.
Is voltage 0 V?
Engine General Information and Diagnosis: For Petrol Engine Model 1A-248
Action Yes
Fuel injectors circuit is
in good condition.
Go to Step 3.
Go to Step 4.
Go to Step 5.
Go to Step 6.
Go to Step 7.
No
Go to Step 2.
Faulty fuel injector.
Faulty fuel injector.
"BLU/BLK" wire is open
or shorted to ground
circuit.
If it is in good condition,
go to "ECM Power and
Ground Circuit Check:
For Petrol Engine
Model".
"PNK", "PNK/BLK",
"PNK/GRN" and/or
"PNK/BLU" wire(s) are
shorted to ground.
"PNK", "PNK/BLK",
"PNK/GRN" and/or
"PNK/BLU" wire(s) are
shorted to power supply
circuit.