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FI
FUEL INJECTION SYSTEM
Fault code No.
37
Symptom
Engine speed is high when the engine is idling.
Used diagnostic code No. 54 (ISC (idle speed control) valve)
Order
Inspection operation item and
probable cause
Operation item and countermeasure
Reinstatement
method
1
Incorrect speed sensor signal
Check the speed sensor.
Check the speed sensor leads.
Check the speed sensor coupler.
Reinstated if the
engine idle speed
is within specifica-
tion after starting
the engine.
2
Throttle valve does not fully close
Check the throttle body.
Refer to
“
THROTTLE BODY AND FUEL INJEC-
TOR
”
.
Check the throttle cables.
Refer to
“
ADJUSTING THE THROTTLE CABLE
FREE PLAY
”
in chapter 3.
3
ISC (idle speed control) valve
stuck fully open
The ISC (idle speed control) valve is stuck fully open
if it does not operate when the main switch is set to
OFF.
(Touch the ISC (idle speed control) valve unit with
your hand and check if it is vibrating to confirm if the
ISC (idle speed control) valve is operating.)
NOTE:
Do not remove the ISC (idle speed control) valve
unit.
4
ISC (idle speed control) valve not
moving correctly
Execute the diagnostic mode (code No. 54)
After the ISC (idle speed control) valve is fully
closed, it opens until it is at the standby opening
position when the engine is started. This operation
takes approximately 12 seconds until it is com-
pleted. Start the engine. If the error recurs, replace
the throttle body assembly.
Fault code No.
39
Symptom
Fuel injector open or short circuit is detected.
Used diagnostic code No. 36 (fuel injector)
Order
Inspection operation item and
probable cause
Operation item and countermeasure
Reinstatement
method
1
Connected condition of connector
Inspect the coupler for any pins
that may have pulled out.
Check the locking condition of the
coupler.
If there is a malfunction, repair it and connect it
securely.
Fuel injector coupler
–
orange/black
Main wiring harness ECU coupler
Sub-wire harness coupler
Reinstated by
starting the engine.
2
Open or short circuit in lead wire.
Repair or replace if there is an open or short circuit.
Between fuel injector coupler and ECU coupler/main
harness
orange/black
–
orange/black
3
Defective fuel injector
Execute the diagnostic mode (code No. 36)
Replace if defective.
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