1986 TOYOTA SUPRA ignition

TROUBLESHOOTING
HINT: Before troubleshooting the turbocharger, first check the engine itself. (Valve clearance, engine com-
pression, ignition timing etc.)
Check intake air system, and repair or replace parts
as necessary. (See page
EG±144)
1. TURBOCHARGING PRESSURE TOO
LOW
2. RESTRICTED INTAKE SYSTEM
6. ERRATIC TURBOCHARGER
OPERATION
3. LEAK IN INTAKE AIR SYSTEM
4. RESTRICTED EXHAUST SYSTEM
5. LEAK IN EXHAUST SYSTEM
INSUFFICIENT ACCELERATION, LACK OF POWER OR EXCESSIVE FUEL
CONSUMPTION
(Possible Cause) Check Procedure and Correction Method)
Check turbocharging pressure. (See page EG±144)
Turbocharging pressure:
61±75 kPa
(062±0.76 kgf/cm
2,
8.8±10.8 psi)
If the pressure is below specifications, begin
diagnosis from item 2.
Check intake air system, and repair or replace parts
as necessary. (See page
EG±144)
Check intake air system, and repair or replace parts
as necessary. (See page
EG±144)
Check intake air system, and repair or replace parts
as necessary. (See page
EG±144)
Check rotation of turbine shaft. If it does not
turn or turns with a heavy drag, replace the
turbocharger assembly.
Check axial and radial play of turbine shaft.
(See page EG±158)
Maximum axial play : 0.110 mm (0.0045 in.)
Maximum radial play : 0.162 mm (0.0064 in.)
If the play is greater than maximum, replace
the turbocharger assembly. EG±142
± ENGINETURBOCHARGER SYSTEM (2JZ±GTE)

DIAGNOSIS SYSTEM
DESCRIPTION
The ECM contains a built±in self±diagnosis system by which
troubles with the engine signal network are detected and a Mal-
function Indicator Lamp on the instrument panel lights up.
By analyzing various signals as shown in a later table (See page
EG±494) the Engine Control Module (ECM) detects system mal-
functions relating to the sensors or actuators.
In the normal mode, the self±diagnosis system monitors 19 items,
indicated by code No. as shown in EG±494. A malfunction indica-
tor lamp informs the driver that a malfunction has been detected.
The lamp goes off automatically when the malfunction has been
repaired, but the diagnostic trouble code(s) remains stored in the
ECM memory (except for code Nos. 16 and 53). The ECM stores
the code(s) until it is cleared by removing the EFI No. 1 fuse with
the ignition switch OFF.
The diagnostic trouble code can be read by the number of blinks
of the malfunction indicator lamp when TE1 and E1 terminals on
the data link connector 1 or 2 are connected. When 2 or more
codes are indicated, the lowest number (code) will appear first.
In the test mode, 13 items, indicated by code No. as shown in
EG±494 are monitored. If a malfunction is detected in any one of
the systems indicated by code Nos. 13, 21, 22, 24, 25, 26, 27, 35,
41, 47, 71 and 78 the ECM lights the malfunction indicator lamp
to warn the technician that a malfunction has been detected. In
this case, TE2 and E1 terminals on the data link connector 2
should be connected as shown later. (See page EG±492).
In the test mode, even if the malfunction is corrected, the malfunc-
tion code is stored in the ECM memory even when the ignition
switch OFF (except code Nos. 43 and 51). The also applies in the
normal mode. The diagnostic trouble mode (normal or test) and
the output of the malfunction indicator lamp can be selected by
connecting the TE1, TE2 and E1 terminals on the data link con-
nector 2, as shown later.
A test mode function has been added to the functions of the self±
diagnosis system of the normal mode for the purpose of detecting
malfunctions such as poor contact, which are difficult to detect in
the normal mode. This function fills up the self±diagnosis system.
The test mode can be implemented by the technician following the
appropriate procedures of check terminal connection and opera-
tion described later. (See page EG±492) EG±490
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

Diagnosis Inspection (Normal Mode)
MALFUNCTION INDICATOR LAMP CHECK
1. The Malfunction Indicator Lamp will come on when the
ignition switch is turned ON and the engine is not running.
HINT: If the malfunction indicator lamp does not light up, pro-
ceed to troubleshooting of the telltale light RH (See page
BE±48).
2. When the engine is started, the malfunction indicator lamp
should go off.
If the light remains on, the diagnosis system has detected a
malfunction or abnormality in the system.
DIAGNOSTIC TROUBLE CODE CHECK
1. Turn ignition switch ON.
2. Using SST, connect terminals between TE1 and E1 of data
link connector 1 or 2.
SST 09843±18020
3. Read the diagnostic trouble code from malfunction indicator
lamp.
HINT: If a diagnostic trouble code is not output, check the TE1
terminal circuit (See page EG±598).
As an example, the blinking patterns for codes; normal, 12
and 31 are as shown on the illustration.
4. Check the details of the malfunction using the diagnostic
trouble code table on page EG±494.
5. After completing the check, disconnect terminals TE1 and
E1, and turn off the display.
HINT: In the event of 2 or more malfunction codes, indication
will begin from the smaller numbered code and continue in
order to the larger.
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±491

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±598.
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±491).
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±492
± ENGINE2JZ±GTE 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±GTE ENGINE TROUBLESHOOTINGEG±493

DIAGNOSTIC TROUBLE CODE CHART
HINT: Parameters listed in the chart may not be exactly the same as your reading due to type of the instruments
or other factors.
DTC
No.
Number of
MIL BlinksCircuitDiagnostic Trouble Code Detecting Condition
Normal
G, NE Signal
(No.1)
G, NE Signal
(No.2)
Ignition Signal
A/T Control
Signal
No code is recorded
No ªNEº or ªG1º and ªG2º signal to ECM for 2 sec. or more after
cranking
No NE signal to ECM for 0.1 sec. or more at 1,000 rpm or
more
NE signal does not pulse 12 times to ECM during the interval
between G1 and G2 pulses
Deviation in G (G1, G2) and NE signal continues for 3 sec. dur-
ing idling (throttle fully closed) after engine warmed up
No IGF signal to ECM for 4~7 consecutive IGT signals with en-
gine speed less than 3,000 rpm
Fault in communications between the engine CPU and A/T CPU
in the ECM
EG±494± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

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

Open or short in heater circuit of main heated oxygen
sensor

Main heated oxygen sensor heater

ECM
 
 
 
 
ON
 
 
 
 
N.A.
 
 
 
 
 
 
 
 
 
 
 
 
Main heated oxygen sensor circuit
Mi h td
 
 
 
 ON
 
 
 
 ON
 
 
 
 

 
 
 
 
EG±525

Main heated oxygen sensor
ON

ON
 Main heated oxygen sensor    
     
     
 
 
 

Open or short in engine coolant temp. sensor circuit

Engine coolant temp. sensor

ECM
 
 
 ON
 
 
 ON
 
 
 
 
 
 EG±530
 
 
 

Open or short in intake air temp. sensor circuit

Intake air temp. sensor

ECM
 
 
 ON
 
 
 ON
 
 
 
 
 
 EG±532
 
Open or short in Main heated oxygen sensor circuit    
 Oen or short in Main heated oxygen sensor circuit

Main heated oxygen sensor    
 Main heated oxygen sensor

Ignition system    
 
gy

ECM    
 
Open or short in injector circuit    
 
Oen or short in injector circuit

Fuel linepressure (injector leak blockage) ON ON  EG 534

Fuel line pressure (injector leak, blockage)

Mechanical system malfunction (skipping teeth ofONONEG±534 
Mechanical system malfunction (skipping teeth of
timing belt)    
 timing belt)

Ignition system
    
 
Ignition system

Compression pressure (foreign object caught in valve)
    
 
Compression pressure (foreign object caught in valve)
M i fl t (i itk)    
 
Mass air flow meter (air intake)
ECM    

ECM
*1, 2: See page EG±502
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±497

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

Open or short in injector circuit

Fuel line pressure (injector leak, blockage)

Mechanical system malfunction (skipping teeth of
timing belt)

Ignition system

Compression pressure (foreign object caught in valve)

Mass air flow meter (air intake)

ECM
 
 
 
 
 
 
 
 
ON
 
 
 
 
 
 
 
 
ON
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
EG±534
 
 
 
 

Open or short in heater circuit of sub heated oxygen
sensor.

Sub heated oxygen sensor

ECM
 
 
 
 
ON
 
 
 
 
N.A.
 
 
 
 
 
 
 
 
 
 
 
 
 

Open or short in sub heated oxygen sensor circuit

Sub heated oxygen sensor

ECM
 
 
 
 
 
ON
 
 
 
 
 
ON
 
 
 
 
 
 
 
 
 
 
EG±540
 
 
 

Open or short in mass air flow meter circuit

Mass air flow meter

ECM
 
 
 ON
 
 
 N.A.
 
 
 
 
 
 EG±544
 
 
 
 
 

Actuator (for waste gate valve)

Short in VSV for waste gate valve circuit

ECM
 
 
 
 
 
ON
 
 
 
 
 
N.A.
 
 
 
 
 

 
 
 
 
 
EG±546
 
 
 

Open or short in turbo pressure sensor circuit

Turbo pressure sensor

ECM
 
 
 ON
 
 
 ON
 
 
 
 
 
 EG±549
 
 
 

ECM
 
 
 
ON
 
 
 
ON
 
 
 
 
 
 
EG±549
*1, 2: See page EG±502.
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±499