Suzuki Grand Vitara XL-7 Service Manual page 185

6-1-46 ENGINE DIAGNOSIS (RHZ ENGINE WITH TRIPLE-CONNECTOR ECM)
STEP
4 Check Fuel Pressure Sensor Circuit
1) Disconnect connector from fuel pressure sensor
with ignition switch turned OFF.
2) Turn ON ignition switch.
3) Check voltage between "LT GRN/BLK" wire
terminal in fuel pressure sensor harness
connector and vehicle body ground.
Is voltage about 5.1 V to 4.88 V?
5 Check Fuel Pressure Sensor Circuit
1) Connect connector to fuel pressure sensor with
ignition switch turned OFF.
2) Turn ON ignition switch.
3) Check voltage between "E228-5" terminal wire in
ECM harness connector and vehicle body
ground.
Is voltage about 5.1 V to 4.88 V?
6 Check Intake Air Pressure Sensor Circuit
1) Disconnect connector from intake air pressure
sensor with ignition switch turned OFF.
2) Turn ON ignition switch.
3) Check voltage between "LT GRN" wire terminal in
intake air pressure sensor harness connector
and vehicle body ground.
Is voltage about 5.1 V to 4.88 V?
7 Check Intake Air Pressure Sensor Circuit
1) Connect connector to intake air pressure sensor
with ignition switch turned OFF.
2) Turn ON ignition switch.
3) Check voltage between "E228-23" terminal wire
in ECM harness connector and vehicle body
ground.
Is voltage about 5.1 V to 4.88 V?
8 Check CMP Sensor Circuit
1) Disconnect connector from CMP sensor with
ignition switch turned OFF.
2) Turn ON ignition switch.
3) Check voltage between "BRN/YEL" wire terminal
in CMP sensor harness connector and vehicle
body ground.
Is voltage about 5.1 V to 4.88 V?
9 Check Intake CMP Sensor Circuit
4) Connect connector to CMP sensor with ignition
switch turned OFF.
5) Turn ON ignition switch.
6) Check voltage between "E228-17" terminal wire
in ECM harness connector and vehicle body
ground.
Is voltage about 5.1 V to 4.88 V?
ACTION YES
Go to Step 5.
Go to Step 6.
Go to Step 7.
Go to Step 8.
Go to Step 9.
Faulty ECM,
substitute a known-
good ECM and
recheck.
NO
"LT GRN/BLK" wire
shorted to other
circuits.
If wire are OK,
substitute a known-
good ECM and
recheck.
Faulty fuel pressure
sensor.
"LT GRN" wire shorted
to other circuits.
If wire are OK,
substitute a known-
good ECM and
recheck.
Faulty intake air
pressure sensor.
"BRN/YEL" wire
shorted to other
circuits.
If wire are OK,
substitute a known-
good ECM and
recheck.
Faulty CMP sensor.