1986 TOYOTA SUPRA Service Repair Manual

 Symbols (Terminals No.) STD Voltage (V) Condition
 EGR (B75) E01 (B80) Below 2.0 Idling
 EGR (B75)±E01 (B80) 9 ~ 14 Engine speed at 3,500 rpm
 VG (B66)±E21 (B28) 0.7 ~ 1.7 Idling
 
 
ISC1 (B35), ISC2 (B34)
Ð E01 (B80)
ISC3 (B33), ISC4 (B32) 
 
Pulse generation
(See page EG±586) 
 Idling when A/C switch ON or OFF
 
VF1 (B29)±E1 (B69) 

1.8 ~ 3.2 

Maintain engine speed at 2,500 rpm for 2
minutes after warming up then return to Idling
 
 OX1 (B48), OX2 (B47)±E1 (B69)
 
 Pulse generation
(See page EG±529)
 
 Maintain engine speed at 2,500 rpm for 2
minutes after warming up
 
HT1 (B71) HT2 (B72) E01 (B80)
 Below 3.0 Idling HT1 (B71), HT2 (B72)±E01 (B80) 9 ~ 14 IG switch ON 
 KNK1 (B50), KNK2 (B49)±E1 (B69)
 
 Pulse generation
(See page EG±563) 
 Idling
 
 
NSW (B76) E1 (B69)
 
 9 ~ 14
 
 IG switch ON
Other shift position in ºPº, ºNº position
 
 
NSW (B76)±E1 (B69) 
 0 ~ 3.0
 
 IG switch ON
Shift position in ºPº, ºNº position
 
 SP1 (A2)±E1 (B69)
 
 
Pulse generation
(See page EG±556) 
 
IG switch ON
Rotate driving wheel slowly
 TE1 (A20)±E1 (B69) 9 ~ 14 IG switch ON
 TE2 (A19)±E1 (B69) 9 ~ 14 IG switch ON
 W (A6)±E1 (B69) 9 ~ 14 Idling
  0 ~ 3.0 IG switch ON
 OD1 (A12)±E1 (B69) 9 ~ 14 IG switch ON
 A/C (A34)±E1 (B69) 7.5 ~14 A/C switch OFF
  0 ~ 1.5 A/C switch ON (At idling)
 ACMG (A23)±E1 (B69) 0 ~ 3.0 A/C switch ON (At idling)
  9 ~ 14 A/C switch OFF
 FPU (B73)±E01 (B80) 9 ~ 14 IG switch ON
  Below 2.0 Restarting at high engine coolant temp.
 ELS (A15)±E1 (B69) 7.5 ~ 14 Defogger switch and taillight switch ON
  0 ~ 1.5 Defogger's switch and taillight switch OFF
 VSV1 (B40)±E1 (B69) Below 3.0 Immediately after racing
  9 ~ 14 Idling
 VSV2 (B39)±E1 (B69) Below 3.0 For 2 sec. after IG switch ON to OFF
  9 ~ 14 Idling
 VSV3 (B38)±E1 (B69) 9 ~ 14 Idling
 
 
 PMC (B60)±E1 (B69)
 
 
 
Below 3.0
 
 
 
Idling (for M/T)
Idling and shift position ºPº, ºNº position
(for AT)
 

PMC (B60)±E1 (B69)
 

9 ~ 14 

Idling and other shift position ºPº, ºNº
position (for A/T))
 
PM1 (B62)±E2 (A65)
 
2.3 ~ 3.0
 
IG switch ON 
 
 
 1.8 ~ 2.4
 
 IG switch ON and apply vacuum 26.7 kPa
(200 mmHg, 7.9 in Hg)
EG±512± 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

CIRCUIT DESCRIPTION
Camshaft position sensors (G1 and G2 signals) are mounted on the intake side of the cylinder head
and the crankshaft position sensor (NE signal) is mounted on the oil pump body. These sensors consist
of a timing rotor and pick up coil.
The G1, G2 timing rotors have 1 tooth each on their outer circumference and are mounted on the intake
camshaft.
When the intake camshaft rotates, the protrusion on the timing rotors and the air gap on the pick up
coil change, causing fluctions in the magnetic field and generating an electromotive force in the pick
up coil.
The NE timing rotor has 12 teeth and is mounted on the crankshaft. The NE signal sensor generates
12 NE signals per engine revolution. The ECM detects the standard crankshaft angle based on the G1,
G2 signals, and the actual crankshaft angle and the engine speed by the NE signals.
DTC No.Diagnostic Trouble Code Detecting ConditionTrouble Area
No ªNEº or ªG1º and ªG2º signal to ECM for 2 sec.
or more after cranking

Open or short in crankshaft position
sensor, camshaft position sensor No.1, No.2
circuit

Crankshaft position sensor

Camshaft position sensor No.1, No.2

Starter

ECM
CIRCUIT INSPECTION
DTC 12 G NE Signal Circuit (No.1)
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±515

INSPECTION PROCEDURE
(See page IG±30).
Check crankshaft position sensor, camshaft position sensors No.1, No.2.
For crankshaft position sensor, remove crankshaft posi-
tion sensor (See page IG±30).
For camshaft position sensor No.1, No.2, disconnect
camshaft position sensor No.1 No.2 connectors.
Measure resistance of crankshaft position sensor, cam-
shaft position sensor No.1 and No.2.
Camshaft
Position Sensor
No.1 and No.2
Camshaft
Position
Sensor
ªColdº is from Ð 10°C (14°F) to 50°C (122°F) and ªHotº
is from 50°C (122°F) to 100°C (212°F).
EG±516± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

Check for open and short in harness and connector between engine control
module and each sensor (See page IN±30).

During cranking or idling, check waveforms between
terminals G1, G2 and G1
, G2
, NE and NE
of
engine control module.
HINT: The correct waveforms are as shown.
Inspect sensor installation and teeth of timing rotor.
INSPECTION USING OSCILLOSCOPE
Replace crankshaft position sensor, camshaft
position sensor No.1, No.2.
Tighten the sensor. Replace timing rotor (Intake
camshaft, crankshaft timing pulley).
Check and replace engine control module.
Repair or replace harness or connector.
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±517

DTC 13 G NE Signal Circuit (No.2)
CIRCUIT DESCRIPTION
Refer to G, NE signal circuit (No.1) on page EG±515
 DTC No. Diagnostic Trouble Code Detecting Condition Trouble Area
 
 
 
 
 
 
 
 
No NE signal to ECM for 0.1 sec. or more at
1,000 rpm or more
 
 
 
 

Open or short in crankshaft position
sensor circuit

Crankshaft position sensor

ECM
 
 
 
 
 
 
13
 
 
 
 
 
 
NE signal does not pulse 12 times to ECM
during the interval between G1 and G2 pulses
 
 
 
 
 
 

Open or short in crankshaft position
sensor circuit

Mechanical system malfunction (skipping
teeth of timing belt, belt stretched)

Crankshaft position sensor

ECM
 
 
 
 
 
 
 
 
Deviation in G (G1, G2) and NE signal
Continues for 3 sec. during idling
throttle fully closed after engine warmed up 
 
 
 

Mechanical system malfunction (skipping
teeth of timing belt, belt stretched)

Camshaft position sensor No. 1, No.2

ECM
INSPECTION PROCEDURE
Inspect sensor installation. Check if any teeth of NE signal plate are broken.
Tighten sensor.
Replace timing rotor.
Adjust valve timing (repair or replace timing belt).
Check valve timing (Check for loose and jumping teeth of timing belt
(See page EG±33)).
Check for intermittent problems.
(See page EG±505)
EG±518± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

DTC 14 Ignition Signal Circuit
CIRCUIT DESCRIPTION
The ECM determines the ignition timing, turns on Tr1 at a predetermined angle (°CA) before the desired ignition
timing and outputs an ignition signal (IGT) º1º to the igniter.
Since the width of the IGT signal is constant, the dwell angle control circuit in the igniter determines the time
the control circuit starts primary current flow to the ignition coil based on the engine rpm and ignition timing one
revolution ago, that is, the time the Tr
2 turns on.
When it reaches the ignition timing, the ECM turns Tr
1 off and outputs the IGT signal ºOº.
This turns Tr
2 off, interrupting the primary current flow and generating a high voltage in the secondary coil which
causes the spark plug to spark. Also, by the counter electromotive force generated when the primary current
is interrupted, the igniter sends an ignition confirmation signal (IGF) to the ECM.
The ECM stops fuel injection as a fail safe function when the IGF signal is not input to the ECM.
 DTC No. Diagnostic Trouble Code Detecting Condition Trouble Area 
 
 
 
14
 
 
 
 
No IGF signal to ECM for 4 ~ 7 consecutive
IGT signals with engine speed less than
3,000 rpm
 
 
 
 

Open or short in IGF circuit from igniter to
ECM

Igniter

ECM
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±519