Suzuki GRAND VITARA Owner's Manual page 259

Step
5 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at "E23-
53" terminal.
3) If OK, measure voltage between "E23-53" terminal of
ECM connector and engine ground with ignition switch
turned ON.
Is voltage 0 V?
6 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at "E23-
56", "E23-53" and "E23-52" terminals.
3) If OK, measure resistance between "BLU/GRN" wire
terminal and each "WHT", "ORN/BLU" wire terminals of
accelerator pedal position (APP) sensor assembly
connector.
Is each resistance infinity?
7 Wire harness check
1) Turn ON ignition switch.
2) Measure voltage between "E23-52" terminal of ECM
connector and engine ground.
Is voltage 0 V?
8 Ground circuit check
1) Connect connectors to ECM with ignition switch turned
OFF.
2) Measure resistance between "BLU/YEL" wire terminal of
accelerator pedal position (APP) sensor assembly
connector and vehicle body ground.
Is resistance below 3
9 Ground circuit check
1) Remove ECM from its bracket with ECM connectors
connected.
2) Check for proper connection of ECM connector at "E23-
51" terminal.
3) If OK, measure resistance between "E23-51" terminal of
ECM connector and engine ground.
Is resistance below 3
10 Accelerator pedal position (APP) sensor assembly
check
1) Check accelerator pedal position sensor (sub) referring
to "Accelerator Pedal Position (APP) Sensor Assembly
Inspection: in Section 1C".
Is output voltage within specified value?
Action
Ω
?
Ω
?
Engine General Information and Diagnosis:
Yes
Substitute a known-
good ECM and recheck.
Go to Step 7.
Go to Step 8.
Go to Step 10.
"BLU/YEL" wire is open
or high resistance
circuit.
Substitute a known-
good ECM and recheck.
1A-204
No
"ORN/BLU" wire is
shorted to power circuit.
"BLU/GRN" wire is
shorted to "WHT" wire
and/or "ORN/BLU" wire.
"BLU/GRN" wire is
shorted to power circuit.
Go to Step 9.
Faulty ECM ground
circuit. If circuit is OK,
substitute a known-
good ECM and recheck.
Replace accelerator
pedal position (APP)
sensor assembly.