1986 TOYOTA SUPRA check engine

Diagnosis Inspection (Test Mode)
Compared to the normal mode, the test mode has an in-
creased sensing ability to detect malfunctions.
It can also detect malfunctions in the starter signal circuit, the
IDL contact signal of the throttle position sensor, air condi-
tioning signal and park/neutral position switch signal.
Furthermore, the same diagnostic items which are detected
in the normal mode can also be detected in the test mode.
DIAGNOSTIC TROUBLE CODE CHECK
1. Initial conditions.
(a) Battery voltage 11 V or more
(b) Throttle valve fully closed
(c) Transmission in neutral position
(d) Air conditioning switched OFF
2. Turn ignition switch OFF
3. Using SST, connect terminals TE2 and E1 of the data link
connector 2.
SST 09843±18020
4. Turn ignition switch ON.
HINT:
wTo confirm that the test mode is operating, check that the
malfunction indicator lamp flashes when the ignition
switch is turned to ON.
wIf the malfunction indicator lamp does not flash, proceed
to troubleshooting of the TE2 terminal circuit on page
EG±484.
5. Start the engine.
6. Simulate the conditions of the malfunction described by the
customer.
7. After the road test, using SST, connect terminals TE1 and E1
of the data link connector 2.
SST 09843±18020
8. Read the diagnostic trouble code on malfunction indicator
lamp on the telltale light RH (See page EG±385).
9. After completing the check, disconnect terminals TE1, TE2
and E1, and turn off the display.
HINT:
wThe test mode will not start if terminals TE2 and E1 are
connected after the ignition switch is turned ON.
wWhen the engine is not cranked, diagnostic trouble
codes º43º (Starter signal) output, but this is not
abnormal.
wWhen the automatic transmission shift lever is in the ºDº,
º2º, ºLº or ºRº shift position, or when the air conditioning
is on or when the accelerator pedal is depressed, code
º51º (Switch condition signal) is output, but this is not
abnormal. EG±386
± ENGINE2JZ±GE ENGINE TROUBLESHOOTING

DIAGNOSTIC TROUBLE CODE CHECK
USING TOYOTA HAND±HELD TESTER
1. Hook up the TOYOTA hand±held tester to the DLC2.
2. Read the diagnostic trouble codes by following the prompts
on the tester screen.
Please refer to the TOYOTA hand±held tester operation's
manual for further details.
DIAGNOSTIC TROUBLE CODE CLEARANCE
1. After repair of the trouble areas, the diagnostic trouble code
retained in the ECM memory must be cleared out by
removing the EFI No.1 fuse (30A) from R/B No.2 for 10
seconds or more, with the ignition switch OFF.
HINT:
wCancellation can also be done by removing the negative
(±) terminal cable from the battery, but in this case, other
memory systems (clock, etc.) will also be cancelled out.
wIf it is necessary to work on engine components
requiring removal of the negative (±) terminal cable from
the battery, a check must first be made to see if a
diagnostic trouble code has been recorded.
2. After cancellation, road test the vehicle to check that a normal
code is now read on the malfunction indicator lamp.
If the same diagnostic trouble code appears, it indicates that
the trouble area has not been repaired thoroughly.
ECM DATA MONITOR USING TOYOTA
HAND±HELD TESTER
1. Hook up the TOYOTA hand±held tester to the DLC2.
2. Monitor the ECM data by following the prompts on the tester
screen.
HINT: TOYOTA hand±held tester has a ºSnapshotº function which
records the monitored data.
Please refer to TOYOTA hand±held tester operator's manual for
further details.
ECM TERMINAL VALUES MEASUREMENT
USING TOYOTA BREAK±OUT±BOX AND
TOYOTA HAND±HELD TESTER
1. Hook up the TOYOTA break±out±box and TOYOTA
handheld tester to the vehicle.
2. Read the ECM input/output values by following the prompts
on the tester screen.
HINT: TOYOTA hand±held tester has a ºSnapshotº function. This
records the measured values and is effective in the diagnosis of
intermittent problems.
Please refer to TOYOTA hand±held tester/TOYOTA break±out
box operator's manual for further details.
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±387

If a malfunction code is displayed during the diagnostic trouble code check in test mode, check the circuit for
that code listed in the table below (Proceed to the page given for that circuit).
EG±409
EG±412
EG±413
EG±418
EG±419
Malfunction
Indicator
Lamp*
1Trouble Area
Normal
ModeTest
Mode
See pageMemory*2
ON
ON
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
ON
ON
ON
ON

Open or short in NE, G circuit

Distributor

Open or short in STA circuit

ECM

Open or short in NE circuit

Distributor

ECM

Open or short in NE circuit

Distributor

ECM

Open or short in IGT or IGT circuit from igniter to ECM

Igniter

ECM

ECM

Open or short in heater circuit of main heated oxygen
sensor (Fr)

Main heated oxygen sensor (Fr) heater

ECM

(Main heated*3) oxygen sensor (Fr) circuit

(Main heated*3) oxygen sensor (Fr)
*1, 2, 3: See page EG±396
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±389

DTC
No.Number of
MIL BlinksCircuitDiagnostic Trouble Code Detecting Condition
EGR System
Malfunction
Fuel Pump
Control Signal
Switch Condition
Signal
(1) 3 sec. or more after engine starts, with closed throttle posi±
tion switch OFF (IDL1)
(2) Park/neutral position switch: OFF
(Shift position in ªRº, ªDº, ª2º, or ªLº position)
(3) A/C switch ON
(3) Open or short in diagnostic signal line (DI) of fuel pump
ECU with engine speed 1,000 rpm or less
(2 trip detection logic)*
4
(2) Open in input circuit of fuel pump ECU (FPC) with engine
speed 1,000 rpm or less
(2 trip detection logic)*
4
(1) Open or short in fuel pump circuit for 1 sec. or more with
engine speed 1,000 rpm or less
(2 trip detection logic)*
4
EGR gas temp. is 70°C (158°F) or less for 1 Ð 4 min. under
conditions (a) and (b):
(2 trip detection logic)*
4
(a) Engine Coolant temp.: 63°C (145°F) or more
(b) EGR operation possible (Example A/T in 3rd speed (5th for
M/T),
A/C ON, 96 km/h (60 mph), Flat road)
*1: ºONº displayed in the diagnostic mode column indicates that the Malfunction Indicator Lamp is lit up when
a malfunction is detected. ºOFFº indicates that the ºCHECKº does not light up during malfunction
diagnosis, even if a malfunction is detected. ºN.A.º indicates that the item is not included in malfunction
diagnosis.
*2: º
º in the memory column indicates that a diagnostic trouble code is recorded in the ECM memory when
a malfunction occurs. ºxº indicates that a diagnostic trouble code is not recorded in the ECM memory even
if a malfunction occurs. Accordingly, output of diagnostic results in normal or test mode is done with the
IG switch ON.
*3: Only for California specification vehicles. EG±396
± ENGINE2JZ±GE ENGINE TROUBLESHOOTING

DTCCircuit
G, NE signal circuit (No.2)
Engine coolant temp. sensor
circuit
Intake air temp. sensor circuit
Throttle position sensor
circuit
CHECK FOR INTERMITTENT PROBLEMS
As described in the preceding paragraph, abnormality detection
ability in the test mode is increased compared to that in the normal
mode, so that when intermittent problems occur in the ECM signal
circuits (G1, G2, NE, THW, THA, VTA1) shown in the table below,
the appropriate diagnostic trouble code is output.
Accordingly, when the diagnostic trouble codes shown in the table
opposite (13, 22, 24, 41) are output during the diagnostic trouble
code check, and inspection of the appropriate circuits reveals no
abnormality, check for intermittent problems as described below.
By checking for intermittent problems, the place where intermittent
problems are occurring due to poor contacts can be isolated.
CLEAR DIAGNOSTIC TROUBLE CODES
See page EG±387.
SET TEST MODE
1. With the ignition switch OFF, using SST, connect the
terminals TE2 and E1 of the data link connector 2.
SST 09843±18020
2. Start the engine and check to see the malfunction indicator
lamp goes off.
PERFORM A SIMULATION TEST
Using the symptom simulation (See page IN±24), apply
vibration to and pull lightly on the wire harness, connector or
terminals in the circuit indicated by the malfunction code.
In this test, if the malfunction indicator lamp lights up, it indi-
cates that the place where the wire harness, connector or ter-
minals being pulled or vibrated has a faulty contact. Check
that point for loose connections, dirt on the terminals, poor fit
or other problems and repair as necessary.
HINT: After cancelling out the diagnostic trouble code in
memory and set the test mode, if the malfunction indicator
lamp does not go off after the engine is started, check thor-
oughly for faulty contacts, etc., then try the check again. If the
malfunction indicator lamp still does not go off, check and re-
place ECM.
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±399

BASIC INSPECTION
In many cases, by carrying out the basic engine check shown in the following flow chart, the location causing
the problem can be found quickly and efficiently. Therefore, use of this check is essential in engine trouble-
shooting.
If there is a problem, and a normal code is displayed, proceed to the matrix chart of problem symptoms on page
EG±408. Make sure that every likely cause of the problem is checked.
EG±408.
Is battery positive voltage 11 V or more when engine is stopped?
Is engine cranked?
Does engine start?
Check air filter.
Charge or replace battery.
Proceed to matrix chart of problem symptoms
on page EG±408.
Repair or replace.
Remove air filter.
Visually check that the air filter is not excessive dirty or
oily.
If necessary, clean the air filter with compressed air. First
blow from inside thoroughly, then blow from outside of
the air filter.
EG±400± ENGINE2JZ±GE ENGINE TROUBLESHOOTING

Check idle speed.
Check ignition timing.
Check idle speed.
(1) Shift transmission into ªNº position.
(2) Warm up engine to normal operating tempera±
ture.
(3) Switch OFF all accessories.
(4) Switch OFF air conditioning.
(5) Connect tachometer test probe to terminal IG
of data link connector 1.
Check idle speed.
Idle speed: 700
50 rpm
wNEVER allow tachometer test probe to touch
ground as it could result in damage to igniter
and/or ignition coil.
wAs some tachometers are not compatible with
this ignition system, we recommend that you
confirm compatibility of your unit become use.
Proceed to matrix chart of problem symptoms
on page EG±408.
Proceed to page EG±18 and continue to trouble-
shoot.
Proceed to matrix chart of problem symptoms
on page EG±408.
(1) Shift transmission into ªNº position.
(2) Warm up engine to normal operating tempera±
ture.
(3) Keep the engine speed at idle.
(4) Using SST, connect terminals TE1 and E1 of data
link connector 1.
SST 09843±18020
(5) Connect a timing light probe to No.1 high±ten-
sion cord.
Check ignitiion timing.
Ignition timing: 10
2° BTDC @ idle
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±401

EG±193
IG±4
EG±408.
(1) Be sure that there is enough fuel in the tank.
(2) Turn ignitiion switch ON.
(3) Using SST, connect terminals FP and +B of data
link connector 1.
SST 09834±18020
Check that there is pressure in the hose from the
fuel filter.
If there is fule pressure, you will hear the sound of
fuel flowing.
Never make a mistake with the terminal connection
position as this will cause a malfunction.
Check fuel pressure.
Check for spark.
Proceed to page EG±193 and continue to trou-
bleshoot.
Proceed to page IG±4 and continue to trouble-
shoot.
Proceed to matrix chart of problem symptoms on
page EG±408.
Disconnect the high±tension cord from the distributor and hold the end about 12.5 mm (1/2º) from the ground.
See if spark occurs while the engine is being cranked.
To prevent excess fuel being injected from the injectors during this test, don't crank the engine for more than
1 Ð 2 seconds at a time.
EG±402± ENGINE2JZ±GE ENGINE TROUBLESHOOTING