TOYOTA SUPRA 1986 Service Repair Manual

 
 
 Trouble Area
 
 
 
Malfunction
Indicator
Lamp*
1
 
 
 Memory*2
 
 
 See page
 
 
Trouble Area
 
 
Normal
Mode 
 
Test
Mode 
 
Memory
 
 
See page
 
 
 
 

Open or short in volume air flow meter circuit

Volume air flow meter

ECM
 
 
 
 
ON
 
 
 
 
N.A.
 
 
 
 

 
 
 
 
EG±438
 
 
 

ECM
 
 
 
ON
 
 
 
ON
 
 
 

 
 
 
EG±441
 
 
 
 

Open or short in throttle position sensor circuit

Throttle position sensor

ECM
 
 
 
 
ON
 
 
 
 
ON
 
 
 
 

 
 
 
 
EG±442
 
 
 
 
 
 
 
 
 

No.1 vehicle speed sensor

Telltale light RH

Open or short in No.1 vehicle speed sensor circuit

ECM
 
 
 
 
 
 
 
 
 
OFF
 
 
 
 
 
 
 
 
 
OFF
 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
EG±445
 
 
 

Open or short in starter signal circuit

Open or short in ignition switch or starter relay circuit

ECM
 
 
 N.A.
 
 
 OFF
 
 
 X
 
 
 EG±448
 
 
 
 
 

Open or short in No.1 knock sensor circuit

No.1 knock sensor (looseness)

ECM
 
 
 
 
 
ON
 
 
 
 
 
N.A.
 
 
 
 
 

 
 
 
 
 
EG±450
 
 
 
 

ECM
 
 
 
 
ON
 
 
 
 
N.A.
 
 
 
 
X
 
 
 
 
EG±450
 
 
 
 
 

Open or short in No.2 knock sensor circuit

No.2 knock sensor (looseness)

ECM
 
 
 
 
 
ON
 
 
 
 
 
N.A.
 
 
 
 
 

 
 
 
 
 
EG±450
*1, 2: See page EG±396.
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±395

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

 
 
 Trouble Area
 
 
 
Malfunction
Indicator
Lamp*
1
 
 
 Memory*2
 
 
 See page
 
 
Trouble Area
 
 
Normal
Mode 
 
Test
Mode 
 
Memory
 
 
See page
 
 
 
 
 
 

Open in EGR gas temp. sensor circuit

Short in VSV circuit for EGR

EGR hose disconnected, valve stuck

Clogged EGR gas passage

ECM
 
 
 
 
 
 
ON
 
 
 
 
 
 
ON
 
 
 
 
 
 

 
 
 
 
 
 
EG±453
 
 
 
 
 
 
 
 
 
 
 
 
 

Open or short in fuel pump ECU circuit

Fuel pump ECU

Fuel pump

ECM power source circuit

ECM
 
 
 
 
 
 
 
 
 
 
 
 
 
OFF
 
 
 
 
 
 
 
 
 
 
 
 
 
ON
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
EG±457
 
 
 
 
 
 

A/C switch circuit

Throttle position sensor IDL circuit

Park/neutral position switch circuit

Accelerator pedal and cable

ECM
 
 
 
 
 
 
N.A.
 
 
 
 
 
 
OFF
 
 
 
 
 
 
X
 
 
 
 
 
 
EG±460
*4: This indicates items for which º2 trip detection logicº is used. With this logic, when a logic malfunction is first
detected, the malfunction is temporarily stored in the ECM memory. If the same case is detected again
during the second drive test, this second detection causes the Malfunction Indicator Lamp to light up.
The 2 trip repeats the same mode a 2nd time. (However, the IG switch must be turned OFF between the
1st trip and 2nd trip).
In the Test Mode, the Malfunction Indicator Lamp lights up the 1st trip a malfunction is detected.
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±397

FAIL±SAFE CHART
If any of the following codes is detected, the ECM enters fail±safe mode.
 DTC No. Fail±Safe Operation Fail±Safe Deactivation Conditions
 14 Fuel cut 1 IGF detected in 3 consecutive ignitions
 16 Torque control prohibited Returned to normal condition
 22 THW is fixed at 80°C (176°F) Returned to normal condition 24 THA is fixed at 20°C (68°F) Returned to normal condition 
 
 
 
 
 
31
 
 
 
 
 
 

Ignition timing fixed at 10°BTDC

Injection time fixed:
(Starting....9 msec.
(IDL ON....3.6 msec.
(IDL OFF....6.7 msec.
 
 
 
 
 
 
KS input 15 times/sec. or more
 
 35
 
 
Atmospheric pressure is fixed at 101.3 kPa
(760 mmHg, 29.92 in.Hg) 
 Returned to normal condition
 
 
 
 

41
 
 
 
 

VTA1 is fixed at 0°
 
 
 
 

The following must each be repeated at least 2
Times consecutively:

0.25 V
VTA
0.95 V

IDL: ON 
 52
 
 Max. timing retardation
 
 IG switch OFF
 53 Max. timing retardation Returned to normal condition
 55 Max. timing retardation IG switch OFF
Back±Up Function
If there is trouble with the program in the ECM and the ignition signals (IGT) are not output from the microcomput-
er, the ECM controls fuel injection and ignition timing at predetermined levels as a back±up function to make
it possible to continue to operate the vehicle.
Furthermore, the injection duration is calculated from the starting signal (STA) and the throttle position signal
(IDL). Also, the ignition timing is fixed at the initial ignition timing, 10°BTDC, without relation to the engine speed.
HINT: if the engine is controlled by the back±up function, the malfunction indicator lamp lights up to warn the
driver of the malfunction but the diagnostic trouble code is not output. EG±398
± 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

PARTS LOCATION
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±403

STANDARD VALUE OF ECM TERMINALS
Connectors of the engine control module are waterproof and are
the bolt type.
For waterproof type connectors, in order to measure the voltage
of ECM terminals and the resistance of connected parts, connect
the inspection sub wire harness between the ECM and vehicle
wire harness, then do the inspection.
The inspection method of inserting a tester probe from the other
side of connector significantly reduces the waterproof perfor-
mance.
Disconnect the connector by fully loosening the bolt.
PREPARATION
1. Turn the ignition switch OFF.
2. Turn up the passenger side floor carpet.
(See page EG±253)
3. Remove the ECM protector.
4. Disconnect the connector from the ECM.
After completely loosening the bolt, the 2 parts of the connec-
tor can be separated.
NOTICE:
wDo not pull the wire harness when disconnecting the con-
nector.
wWhen disconnecting the connector, the ECM's back±up
power source is cut off, so the malfunction codes, etc. re-
corded in the ECM memory are cancelled.
wNever insert a tester probe or male terminal used for in-
spection purposes into the female terminal of the vehicle
wire harness. Otherwise, the female terminal may be wid-
ened, which can result in faulty connection.
5. Connect SST (check harness ºAº) between the ECM and
connector of the vehicle wire harness.
SST 09990±01000
HINT: The arrangement of the check connector terminals are
the same as those of the ECM.
See page EG±405.
6. Disconnect the SST.
SST 09990±01000
7. Reconnect the connector to the ECM.
(a) Match the male connector correctly with the female
connector, then press them together.
(b) Tighten the bolt.
Make sure the connector is completely connected by
tightening the bolt until there is a clearance of less than
1 mm (0.04 in.) between the bottom of the male connec-
tor and the end of the female connector.
8. Install the ECM protector and floor carpet. EG±404
± ENGINE2JZ±GE ENGINE TROUBLESHOOTING