1986 TOYOTA SUPRA check engine light

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

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

CIRCUIT DESCRIPTION (Cont'd)
DIAGNOSTIC TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diagnostic
trouble code is no longer detected.
Malfunction: (Main heated() Oxygen Sensor Detection
(Vehicle Speed)
80 km/h (50 mph)
64 km/h (40 mph)
It is vital that this test routine is adhered to detect the malfunction:
(1) Disconnect the EFI No.1 fuse (30 A) for 10 sec. or more, with IG switch OFF. Initiate test
mode (Connect terminal TE2 and E1 of data link connector 2 with IG switch OFF).
(2) Start the engine and warm up with all ACC switched OFF.
(3) Idle the engine for 3 min.
(4) Accelerate gradually within the range 1,300 ~ 1,700 rpm (dentered around 1,500 rpm) with
the A/C switched ON and D position for A/T (5th for M/T).
HINT:
Ensure engine rpm does NOT fall below 1200 rpm.

Gradually depress the accelerator pedal at a suitable rate to comply with the test
requirements on the above graph.

Never allow engine rpm to drop at any time during the test.
(5) Maintain the vehicle speed at 64 Ð 80 km/h (40 Ð 50 mph).
(6) Keep the vehicle running for Ð 2 min. after starting acceleration.
HINT: If a malfunction exists, the Malfunction Indicator Lamp will light up after approx. 60 sec.
from the start of acceleration.
NOTICE: If the conditions in this test are not strictly followed, detection of the malfunction
will not be possible.
*: Main heated oxygen sensor only for California specification vehicles EG±420
± ENGINE2JZ±GE ENGINE TROUBLESHOOTING

CIRCUIT DESCRIPTION (Cont'd)
DIAGNOSTIC TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diagnostic
trouble code is no longer detected.
Malfunction: Open or Short in (Main Heated*) Oxygen Sensor
HINT: Before this test, check the feedback voltage for oxygen sensor.
(1) Disconnect the EFI No.1 fuse (30 A) for 10 sec. or more, with IG switch OFF. Initiate test
mode (Connect terminal TE2 and E1 of data link connector 2 with IG switch OFF).
(2) Start the engine and warm up.
(3) Idle the engine for 3 min.
(4) Race the engine at 2,000 rpm for 90 sec.
HINT: If a malfunction exists, the malfunction indicator lamp will light up during step (4).
NOTICE: If the conditions in this test are not strictly followed, detection of the malfunction
will not be possible.
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±429

See page
EG±421
(1) Disconnect the EFI No.1 fuse (30A) for 10 sec. or more, with IG switch OFF.
Initiate test mode (Connect terminal TE2 and E1 of data link connector 2
with IG switch OFF).
(2) Start the engine and warm up with all ACC switched OFF.
(3) Idle the engine for 5 min.
(After the engine is started, do not depress the accelerator pedal.)
(4) If the malfunction is not detected during idling, racing the engine without any load at
approx. 2,000 rpm for 60 sec.

HINT: If a malfunction exists, the malfunction indicator lamp will light up during the 5 min. idling
period or within 60 sec. of starting racing.
NOTICE: If the conditions in this test are not strictly followed, detection of the malfunction
will not be possible.
CIRCUIT DESCRIPTION (Cont'd)
DIAGNOSTIC TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diagnostic
trouble code is no longer detected.
Malfunction: Open or Short in Injector circuit, Injector Leak or Blockage.
WIRING DIAGRAM
See page EG±421 for the WIRING DIAGRAM.
*: Only for California specification vehicles
EG±430± ENGINE2JZ±GE ENGINE TROUBLESHOOTING

CIRCUIT DESCRIPTION (Cont'd)
DIAGNOSTIC TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diagnostic
trouble code is no longer detected.
(1) Disconnect the EFI No.1 fuse (30A) for 10 sec. or more, with IG switch OFF.
Initiate test mode (Connect terminal TE2 and E1 of data link connector 2 with
IG switch OFF).
(2) Start the engine and warm up with all ACC switch OFF.
(3) Deive the vehicle at 80 ~ 88 km/h (50 ~ 55 mph) for 10 min. or more.
(4) Stop at a safe place and idle the engine for 2 min. or less.
(5) Accelerate to 96 km/h (60 mph) with the throttle valve fully open.
HINT: If a malfunction exists, the malfunction indicator lamp will light up during step (5).
NOTICE: If the conditions in this test are not strictly followed, detection of the malfunction
will not be possible.
Malfunction: Open or Short in Sub Heated Oxygen Sensor
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±435

INSPECTION PROCEDURE
(See page
EG±404)
(See page BE±48)).
Check voltage bertween terminal SP1 of engine control module connector
and body ground.
Check and replace engine control module.
(1) Shift the shift lever to N position.
(2) Jack up one of the rear wheel.
(3) Connect SST (check harness ªAº).
(See page EG±404)
SST 09990±01000
(4) Disconnect power steering ECU connector
and cruise control ECU connector.
(5) Turn ignition switch ON.
Measure voltage between terminal SP1 of engine
control module connector and body ground when
the wheel is turned slowly.
Voltage is generated intermittently.
Repair or replace harness or connector between
ECM and telltale light RH.
Check operation of odometer and trip meter (telltale light RH
(See page
BE±48)).
Check operation of No.1 vehicle speed sensor (See page BE±46).
Replace No.1 vehicle speed sensor.
Repair or replace harness or connector between
telltale light RH and No.1 vehicle speed sensor.
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±447