Suzuki GRAND VITARA Owner's Manual page 155

Step
4 ECM voltage check
1) Turn OFF ignition switch.
2) Remove ECM from its bracket with ECM connectors
connected.
3) Check for proper connection of ECM connector at "C37-
53" terminal.
4) If OK, measure voltage between "C37-53" terminal of
ECM connector and engine ground with ignition switch
turned ON.
Is voltage 4 – 6 V?
5 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between "C37-53" terminal of ECM
connector and engine ground.
Is resistance infinity?
6 Wire harness check
1) Measure voltage between "BLK" wire terminal of electric
throttle body assembly connector and engine ground
with ignition switch turned ON.
Is voltage 4 – 6 V?
7 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at "C37-
54" and "C37-41" terminals.
3) If OK, measure resistance between "GRN" and "BLK"
wire terminals of electric throttle body assembly
connector.
Is resistance infinity?
8 Wire harness check
1) Measure resistance between "BLK" wire terminal of
electric throttle body assembly connector and engine
ground with ignition switch turned OFF.
Is resistance infinity?
9 Electric throttle body assembly check
1) Check throttle pedal position sensor referring to "Throttle
Position Sensor Performance Check" under "Electric
Throttle Body Assembly On-Vehicle Inspection: in
Section 1C".
Is output voltage within specified value?
Action
Engine General Information and Diagnosis:
Yes
"WHT" wire is open or
high resistance circuit.
Substitute a known-
good ECM and recheck.
Go to Step 9.
Go to Step 8.
Substitute a known-
good ECM and recheck.
Substitute a known-
good ECM and recheck.
1A-100
No
Go to Step 5.
"WHT" wire is shorted to
ground circuit.
Go to Step 7.
"BLK" wire is shorted to
"GRN" wire.
"BLK" wire is shorted to
ground circuit.
Replace electric throttle
body assembly.