Page 1977 of 2543
Check EFI main relay.
Remove EFI main relay from R/B No.2.
Check continuity between terminals of EFI main
relay shown below.
Replace EFI main relay.
(1) Apply battery voltage between terminals 1
and 2.
(2) Check continuity between terminals 3 and 5.
Repair or replace harness or connector.
Check and repair harness or connector between
EFI No.1 fuse and battery.
Check for open and short in harness and connector between terminal M±REL
of engine control module and body ground(See page
IN±30).
Terminals 3 and 5
Terminals 3 and 5
Terminals 1 and 2
Open
Continuity
Continuity
(Reference value 72 )
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±469
Page 1978 of 2543
Back Up Power Source Circuit
CIRCUIT DESCRIPTION
Battery positive voltage is supplied to terminal BATT of the ECM even when the ignition switch is off for use by
the diagnostic trouble code memory and air±fuel ratio adaptive control value memory, etc.
EG±470± ENGINE2JZ±GE ENGINE TROUBLESHOOTING
Page 1979 of 2543
INSPECTION PROCEDURE
Check EFI No.1 Fuse.
Remove EFI No.1 fuse from R/B No.2.
Check continuity of EFI No.1 fuse.
Continuity
Check for short in the harness and all the com-
ponents connected to EFI No.1 fuse (See Electri-
cal Wiring Diagram).
Connect SST (check harness ªAº).
(See page EG±404)
SST 09990±01000
Measure voltage between terminal BATT of en-
gine control module connector and body ground.
Voltage: 9 Ð 14 V
Check and replace engine control module.
Check and repair harness or connector between
engine control module and EFI No.1 fuse, EFI No.1
fuse and battery.
Proceed to next circuit inspection shown on matrix
chart (See page
EG±408).
Check voltage between terminal BATT of engine control module connector
and body ground.
Are the diagnostic trouble codes still in the memory when the ignition switch
is turned OFF?
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±471
Page 1980 of 2543
Injector Circuit
CIRCUIT DESCRIPTION
The injectors are located in the intake manifold. They inject fuel into the cylinders based on the signals
from the engine control module.
INSPECTION USING OSCILLOSCOPE
With the engine idling measure waveform between terminals #10 ~ 60 and E01 of engine
control module.
HINT: The correct waveform is as shown.
EG±472± ENGINE2JZ±GE ENGINE TROUBLESHOOTING
Page 1981 of 2543
INSPECTION PROCEDURE
(See page EG±404)
Check voltage between terminals # 10 ~ 60 of engine control module and
body ground.
(1) Connect SST check harness ªAº).
(See page EG±404)
SST 09990±01000
(2) Turn ignition switch ON.
Measure voltage between terminals #10
~ 60 of
engine control module and body ground.
Voltage: 9 Ð 14 V
Check for short in the harness and all the compo-
nents connected to AM2 fuse.
Remove AM2 fuse from R/B No.2.
Check continuity of AM2 fuse.
Continuity
Check and repair harness or connector between en-
gine control module and battery.
Check AM2 Fuse.
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±473
Page 1982 of 2543
(See page
EG±202)
Check for open in harness and connector between terminal E)1, EO2 of ECM
connector and body ground (See page
IN±30).
Disconnect injector connector. (See page EG±202)
Measure resistance of injector.
Resistance: 13.4 Ð 14.2 at 20°C (68°F)
Check injector volume of injector.
(See page EG±207)
Injection volume
70 Ð 88 cc/15 sec.
(4.3 Ð 5.4 cu in./15 sec.)
Difference between each injector:
Less than 9 cc (0.5 cu in.)
Leakage
Fuel drop: One drip or less per minute
Replace injector.
Check and replace engine control module.
Check injectors.
Repair or replace harness or connector.
Replace injector.
Check and replace engine control module.
EG±474± ENGINE2JZ±GE ENGINE TROUBLESHOOTING
Page 1983 of 2543
CIRCUIT DESCRIPTION
The IAC valve is situated on the intake chamber. Intake
air bypassing the throttle valve is directed to the IAC
valve through a passage.
A step motor is built into the IAC valve. It consists of 4
coils, a magnetic rotor, valve shaft and valve.
When current flows to the coils due to signals from the
ECM, the rotor turns and moves the valve shaft forward
or backward, changing the clearance between the
valve and the valve seat.
In this way the intake air volume bypassing the throttle
valve is regulated, controlling the engine speed.
There are 125 possible positions to which the valve can
be opened.
With the engine idling measure wave forms
between terminals ISC1, ISC2, ISC3, ISC4
and E01 of engine control module when
A/C switch ON or OFF.
HINT:
The correct waveforms are as shown.
INSPECTION USING OSCILLOSCOPE
IAC Valve Circuit
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±475
Page 1984 of 2543
EG±476± ENGINE2JZ±GE ENGINE TROUBLESHOOTING