1986 TOYOTA SUPRA ignition

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

Open or short in throttle position sensor circuit

Throttle position sensor

ECM
 
 
 
ON
 
 
 
ON
 
 
 

 
 
 
EG±552
 
 
 
 
 
 
 
 
 

No.1 vehicle speed sensor

Telltale light RH

Open or short in No.1 vehicle speed sensor circuit

ECM
 
 
 
 
 
 
 
 
 
OFF
 
 
 
 
 
 
 
 
 
OFF
 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
EG±556
 
 
 

Open or short in starter signal circuit

Open or short in ignition switch or starter relay circuit

ECM
 
 
 
N.A
 
 
 
OFF
 
 
 
X
 
 
 
EG±559
 
 
 

Open or short sub±throttle position sensor circuit

Sub±throttle position sensor

ECM
 
 
 
OFF
 
 
 
ON
 
 
 

 
 
 
EG±552
 
 
 

Open or short in No.1 knock sensor circuit

No.1 Knock sensor (loosensess)

ECM
 
 
 
ON
 
 
 
N.A
 
 
 

 
 
 
EG±561
 
 
 

ECM
 
 
 
ON
 
 
 
N.A
 
 
 
X
 
 
 
EG±561
 
 
 

Open or short in No.2 knock sensor circuit

No.2 Knock sensor (looseness)

ECM
 
 
 
ON
 
 
 
N.A
 
 
 

 
 
 
EG±561
*1,
2: See page EG±502.
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±501

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
 
 6 IGF signals detected in 6 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
 
 
 
 
 
 
Volume of air flowing is measured by turbo pressure
Sensor to determine injection volume and ignition
Timing
 
 
 
 
 
 
Returned to normal condition
 
 34
 
 Fuel cut
 
 Returned to normal condition
  Turbo  
  
Turbo
Pressure Fuel cut Returned to normal condition
 35 Sensor  
 
 
35
 
 
BARO
Sensor 
 
Atmospheric pressure is fixed at
101.3 kPa (760 mmHg, 29.92 inVHg) 
 Returned to normal condition
 
 
 
 
41
 
 
 
 
VTA1 is fixed at closed throttle position
 
 
 
 
The following must each be repeated at
least 2 times consecutively:

0.1 V
VTA1
0.95 V

IDL: ON
 
 
 
47
 
 
 
VTA2 is fixed at wide open throttle
Position 
 
 
The following must be repeated at least 2
times consecutively

0.1 V
VTA2
0.95 V
 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±504
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

G, NE signal circuit (No.2)
Engine coolant temp. sensor
circuit
Intake air temp. sensor circuit
Throttle position sensor
circuit
Sub±throttle position sensor
circuit
CircuitDTC
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, VTA2) 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, 47) are output during the diagnostic
trouble code check, and inspection of the appropriate circuits re-
veals 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±493.
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 indicates
that the place where the wire harness, connector or terminals be-
ing pulled or vibrated has 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 thoroughly for faulty con-
tacts, etc., then try the check again, if the malfunction indicator
lamp still does not go off, check and replace ECM.
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±505

(See page EG±20)
Check idle speed.
Proceed to matrix chart of problem symp-
toms on page EG±514.
(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: 650  50 rpm

Never allow tachometer test probe to touch
ground as it could result in damage to igniter
and/or ignition coil.

As some tachometers are not compatible
with this ignition system, we recommended
that you confirm the compatibility of your
unit before use.
Check ignition timing.
(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 clip to the check wire.
(See page EG±20)
Check ignition timing.
Ignition timing: 10 2° BTDC @ idle
Proceed to matrix chart of problem symp-
toms on page EG±514.
Proceed to page EG±518 and continue to
troubleshoot.
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±507

(See page
IG±26)
Check fuel pressure.
Proceed to page EG±264 and continue to
troubleshoot.
(1) Be sure that there is enough fuel in the tank.
(2) Turn ignition switch ON.
(3) Using SST, connect terminals FP and +B of
data link connector 1.
SST 09843±18020
Check that there is pressure in the hose from the fuel
filter.
If there is fuel pressure, you will hear the sound of fuel
flowing.
Never make a mistake with the terminal con-
nection position as this will cause a malfunc-
tion.
Check for spark.
Proceed to page IG±21 and continue to trou-
bleshoot.
Proceed to matrix chart of problem symptoms
on page EG±514.
(1) Remove ignition coil (See page IG±26)
(2) Remove spark plug.
(3) Install the spark plug to the ignition coil, and connect
the ignition coil connector.
(4) Ground the spark plug.
Check if spark occurs while 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±508± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

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±324)
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±511.
6. Disconnect the SST.
SST 09990±01000
7. Reconnect the connector to the ECM.
(a) M a t c h t h e m a l e connector correctly with the female
connector, then press them together.
(b) Tighten the bolt.
Make sure the connector is completely connected by tighten-
ing the bolt until there is a clearance of less than 1 mm (0.04
in.) between the bottom of the male connector and the end
of the female connector.
8. Install the ECM protector and floor carpet. EG±510
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

REFERENCE VALUE OF ECM DATA
HINT: ECM data can be monitored by TOYOTA hand±held
tester.
1. Hook up the TOYOTA hand±held tester to DLC2.
2. Monitor ECM data by following the prompts on the tester
screen.
Please refer to the TOYOTA hand±held tester operator's manual
for further details.
REFERENCE VALUE 
 Item
 
 Inspection condition
 
 Reference value
 
 INJECTOR 
 
Engine cold to hot
Engine idling at normal operating temp.*1
 
 
Gradually decreases
Approx. 1.8 msec.
 IGNITION Increase engine speed Gradually increases
 
 
 
 
IAC STEP #
 
 
 
 
Engine idling at normal operating temp..*1
A/C switch ON
A/T shifting in ºDº position
Ignition switch ON (Engine off)
 
 
 
 
20 ~ 30 steps
Step increases
Step increases
Approx. 125 steps`
 ENGINE SPEED RPM kept stable (Comparison with tachometer) No great changes
 
 MAF
 
 Engine idling at normal operating temp..*1
Increase engine speed
 
 Approx. 3.8 g/s
Gradually increases
 ECT Engine at normal operating temp. 75±95°C (185±203°F).*2 
 
 THROTTLE
 
 
 
Closed throttle position
Wide open throttle
From closed throttle position to wide open throttle
 
 
 
Below 5°
Above 70°
Gradually increases 
 
 
VEHICLE SPD
 
 
 
During driving
(Comparison with speedometer)
 
 
 
No large differences
 TARGET A/FL Engine idling at normal operating temp. 2.50 + 1.25 V*3
 A/F FB LEFT RPM stable at 2,500 rpm with normal operating temp. ON
 KNOCK FB Depress throttle pedal suddenly during idling ON 
 STA SIGNAL 
 During cranking 
 ON
 CTP SIGNAL Closed throttle position ON
 A/C SIGNAL A/C switch ON ON
 
 PNP SIGNAL.*4 
 
When shifting from ºPº or ºNº position into a position
other than ºPº or ºNº 
 GEAR
 OxL RPM stable at 2,500 rpm with normal operating temp. RICH LEAN is repeated
*1: All accessories and A/C switched OFF
*
2: If the engine coolant temp. sensor circuit is open or shorted, the ECM assumes an engine coolant temp.
value of 80°C (176°F).
*
3: When feedback control is forbidden, 0 V is displayed.
*
4: A/T only
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±513

Suspect area
See page
Symptom
Engine does not crank
No initial combustion
No complete combustion
Engine cranks normally
Cold engine
Hot engine
Incorrect first idle
High engine idle speed
Low engine idle speed
Rough idling
Hunting
Hesitation/Poor acceleration
Muffler explosion (after fire)
Surging
Soon after starting
After accelerator pedal depressed
After accelerator pedal released
During A/C operation
When shifting N to D
Does not
start
Difficult to
start
Poor Idling
Engine Stall
Poor
Driveability
Back up power source circuitECM power source circuitPark/neutral position switch circuitSwitch condition signal circuitEGR systemStarter signal circuitMass air flow meter circuitInjector circuitIAC valve circuitFuel pump control circuitA/C signal circuit (Compressor circuit)Turbo control circuitVSV circuit for fuel Pressure ControlCompressionSpark plugIgnition signal circuit (Spark test)Starter and Starter relayIgnition coilEngine control module (ECM)Theft deterrent ECUA/T faulty
EG±544EG±559EG±564EG±571EG±574EG±576EG±581EG±583EG±586EG±568EG±595EG±589AC±62ST±3
,
12
IG±21IG±23IG±22EG±9AT2±101BE±123IN±35
MATRIX CHART OF PROBLEM SYMPTOMS
When the malfunction code is not confirmed in the diagnostic trouble code check and the problem still can not
be confirmed in the basic inspection, proceed to this matrix chart and troubleshoot according to the numbered
order given below. EG±514
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING