traction control TOYOTA SUPRA 1986 Service Repair Manual

CIRCUIT DESCRIPTION
The throttle position sensor is mounted in the throttle
body and detects the the throttle valve opening angle.
When the throttle valve is fully closed, the IDL contacts
in the throttle position sensor are on, so the voltage at
the terminal IDL of the ECM becomes 0 V. At this time,
a voltage of approximately 0.7 V is applied to the termi-
nal VTA of the ECM. When the throttle valve is opened,
the IDL contacts go off and thus the power source volt-
age of approximately 12 V in the ECM is applied to the
terminal IDL of the ECM. The voltage applied to the ter-
minal VTA of the ECM increases in the proportion to
the opening angle of the throttle valve and becomes
approximately 3.2 ± 4.9 V when the throttle valve is ful-
ly opened. The ECM judges the vehicle driving condi-
tions from these signals input from the terminals VTA
and IDL, and uses them as one of the conditions for de-
ciding the air±fuel ratio correction, power increase
corrections and fuel±cut control etc. The sub±throttle
position sensor is built and operates in the same way
as the main throttle position sensor. This sensor is
used for traction control. The sub±throttle valve is
opened and closed by the sub±throttle actuator ac-
cording to signals from the TRAC ECU to control the
engine output.
Open or short in throttle position sensor circuit
for 0.5 sec. or more
Open or short in sub±throttle position sensor
circuit for 0.5 sec. or more

Open or short in throttle position sensor
circuit

Throttle position sensor

ECM

Open or short in sub±throttle position
sensor circuit

Sub±throttle position sensor

ECM
HINT:
Diagnostic trouble code 41 is for the throttle position sensor circuit.
Diagnostic trouble code 47 is for the sub±throttle position sensor circuit.

When the connector for the throttle position sensor(s) is disconnected, diagnostic trouble code 41
or 47 is not displayed. Diagnostic trouble code 41 or 47 is displayed only when there is an open
or short in the VTA signal circuit of the throttle position sensor(s).

Signals from the throttle position sensor(s) are also input to the TRAC ECU, so when a malfunc±
tion occurs on the TRAC side, code 41 or 47 may be displayed.
DTC 41 47 Throttle Position Sensor(s) Circuit
EG±552± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

(See page EG±397).
CIRCUIT DESCRIPTION
The EGR system is designed to recirculate the exhaust gas, controlled according to the driving condi-
tions, back into the intake air±fuel mixture. It helps to slow down combustion in the cylinder and thus
lower the combustion temperature which, in turn, reduces the amount of NOx emission. The amount
of EGR is regulated by the EGR vacuum modulator according to the load.
If even one of the following conditions is fulfilled,
the VSV is turned ON by a signal from the ECM.
This results in atmospheric air acting on the EGR
valve, closing the EGR valve and shutting off the
exhaust gas (EGR cut±OFF).

Engine coolant temp. below 50°C (122°F)

During deceleration (Throttle valve closed)

Light engine load (amount of intake air very
small).

Engine speed over 5,200 rpm

Traction control is operating
DTC No.Diagnostic Trouble Code Detecting ConditionTrouble Area
EGR gas temp. is 70°C (158°F) or less for 1 ~
4 min. under conditions (a) and (b):
(2) trip detection logic)*
(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)

Open in EGR gas temp. sensor circuit

Short in VSV circuit for EGR

EGR hose disconnected, valve stuck

Clogged EGR gas passage

ECM
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 by confirming that diag±
nostic trouble code is no longer detected.
DTC 71 EGR System Malfunction
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±453

15
TROUBLESHOOTING / ABBREVIATIONS
DISCONNECTION AND CONNECTION OF BOLT
TYPE CONNECTORS
For engine control module (engine and electronically controlled
transmission ECU) in this vehicle, connectors are used which
require a bolt built into the connector to be screwed down to
securely connect the connector.
1. Disconnect the connector
After completely loosening the bolt, the two parts of the
connector can be separated.
NOTICE:
Do not pull the wire harness when disconnecting the
connector.
2. Connect the connector
NOTICE:
Before connecting the connector, always check that the
terminals are not bent or damaged.
(a) Match the guide section of the male connector
correctly with the female connector, then press them
together.
(b) Tighten the bolt.
Make sure the connectors are completely connected,
by tightening the bolt until there is a clearance of less
than 1 mm (0.04 in.) between the bottom of male
connector and the end of female connector.
ABBREVIATIONS
The following abbreviations are used in this manual.
ABS = Anti±Lock Brake System O/D = Overdrive
A/C = Air Conditioning PPS = Progressive Power Steering
ACIS = Acoustic Control Induction System R/B = Relay Block
A/T = Automatic Transmission RH = Right±Hand
COMB. = Combination SFI = Sequential Multiport Fuel Injection
ECU = Electronic Control Unit SRS = Supplemental Restraint System
EFI = Electronic Fuel Injection SW = Switch
EGR = Exhaust Gas Recirculation TDCL = Total Diagnostic Communication Link
EVAP = Evaporative Emission TEMP. = Temperature
ISC = Idle Speed Control TRAC = Traction Control System
J/B = Junction Block VSV = Vacuum Switching Valve
LH = Left-Hand w/ = With
M/T = Manual Transmission w/o = Without
* The titles given inside the components are the names of the terminals (terminal codes) and are not treated
as being abbreviations.

15
ABBREVIATIONS
DISCONNECTION AND CONNECTION OF BOLT
TYPE CONNECTORS
For engine control module (engine and electronically controlled
transmission ECU) in this vehicle, connectors are used which
require a bolt built into the connector to be screwed down to
securely connect the connector.
1. Disconnect the connector
After completely loosening the bolt, the two parts of the
connector can be separated.
NOTICE:
Do not pull the wire harness when disconnecting the
connector.
2. Connect the connector
NOTICE:
Before connecting the connector, always check that the
terminals are not bent or damaged.
(a) Match the guide section of the male connector
correctly with the female connector, then press them
together.
(b) Tighten the bolt.
Make sure the connectors are completely connected,
by tightening the bolt until there is a clearance of less
than 1 mm (0.04 in.) between the bottom of male
connector and the end of female connector.
ABBREVIATIONS
The following abbreviations are used in this manual.
ABS = Anti±Lock Brake System O/D = Overdrive
A/C = Air Conditioning PPS = Progressive Power Steering
ACIS = Acoustic Control Induction System R/B = Relay Block
A/T = Automatic Transmission RH = Right±Hand
COMB. = Combination SFI = Sequential Multiport Fuel Injection
ECU = Electronic Control Unit SRS = Supplemental Restraint System
EFI = Electronic Fuel Injection SW = Switch
EGR = Exhaust Gas Recirculation TDCL = Total Diagnostic Communication Link
EVAP = Evaporative Emission TEMP. = Temperature
ISC = Idle Speed Control TRAC = Traction Control System
J/B = Junction Block VSV = Vacuum Switching Valve
LH = Left-Hand w/ = With
M/T = Manual Transmission w/o = Without
* The titles given inside the components are the names of the terminals (terminal codes) and are not treated
as being abbreviations.

25
Position of Parts in Engine Compartment
[2JZ±GTE]
I 1 Idle Air Control Valve (ISC Valve) R 1Radiator Fan Motor
I 2 Igniter R 2Radiator Fan Relay No. 1
I 3 Igniter R 3Radiator Fan Relay No. 2
I 6 Ignition Coil No. 1
I 7 Ignition Coil No. 2 S 1 SFI Resistor (EFI Resistor)
I 8 Ignition Coil No. 3 S 2Starter
I 9 Ignition Coil No. 4 S 3Starter
I 10 Ignition Coil No. 5 S 4 Sub Throttle Actuator
I 11 Ignition Coil No. 6 S 5 Sub Throttle Position Sensor
I 12 Injector No. 1
I 13 Injector No. 2 T 1 Theft Deterrent Horn
I 14 Injector No. 3 T 2 Throttle Position Sensor
I 15 Injector No. 4 T 3 Traction Brake Actuator
I 16 Injector No. 5 T 4 Traction Pump and Motor
I 17 Injector No. 6 T 14 Turbo Pressure Sensor
K 1 Knock Sensor (on Front Side) V 2 VSV (for EGR)
K 2 Knock Sensor (on Rear Side) V 3 VSV (for EVAP)
V 4 VSV (for Exhaust Bypass Valve)
M 1 Mass Air Flow (Air Flow Meter) V 5 VSV (for Exhaust Gas Control Valve)
V 6 VSV (for Fuel Pressure Up)
N 1 Noise Filter V 7 VSV (for Intake Air Control Valve)
V 8 VSV (for Waste Gate Valve)
O 1 O/D Direct Clutch Speed Sensor V 10 Vehicle Speed Sensor (Speed Sensor) No. 1 (for
O 2 Oil Pressure SW Combination Meter)
V 11 Vehicle Speed Sensor (Speed Sensor) No. 2 (for
P 1 PPS Solenoid Electronically Controlled Transmission)
P 2 Park/Neutral Position SW (Neutral Start SW),
Back±Up Light SW and A/T Indicator Light SW W 1 Washer Motor
(for A/T)

28
ELECTRICAL WIRING ROUTING
Position of Parts in Instrument Panel
A 12 A/C Amplifier B 5 Blower Motor Control Relay
A 13 A/C Amplifier B 6 Buckle SW LH
A 14 A/C Amplifier B 7 Buckle SW RH
A 15 A/C Evaporator Temp. Sensor
A 16 A/C Room Temp. Sensor C 5 Center Airbag Sensor Assembly
A 17 A/C Solar Sensor C 6 Cigarette Lighter
A 18 ABS ECU C 7 Cigarette Lighter Illumination
A 19 ABS ECU C 8 Clock
A 20 ABS and Traction ECU C 9 Clutch Start SW
A 21 ABS and Traction ECU C 10 Combination Meter
A 22 ABS and Traction ECU C 11 Combination Meter
A 23 ABS Lateral Acceleration Sensor C 12 Combination Meter
A 24 Air Inlet Control Servo Motor C 13 Combination SW
A 25 Air Mix Control Servo Motor C 14 Combination SW
A 26 Air Vent Mode Control Servo Motor C 15 Cruise Control Clutch SW
A 27 Airbag Squib (Steering Wheel Pad) C 16 Cruise Control ECU
A 28 Airbag Squib (Front Passenger Airbag Assembly)
A 29 Ashtray Illumination D 5 Data Link Connector 2 (TDCL)
A 30 Auto Antenna Control Relay D 6 Daytime Running Light Relay (Main)
D 7 Diode (for Interior Light)
B 3 Blower Motor D 8 Diode (for Idle-Up)
B 4 Blower Motor Control Relay

29
Position of Parts in Instrument Panel
E 8 Electronically Controlled Transmission Pattern O 5 O/D Main SW and A/T Indicator Light (for Shift
Select SW Lever)
E 9 Engine Control Module (Engine and Electronically
Controlled Transmission ECU) P 4 PPS ECU
E 10 Engine Control Module (Engine and Electronically P 5 Parking Brake SW
Controlled Transmission ECU)
E 11 Engine Coolant Temp. Sensor (Water Temp. Sensor) R 4 Radio and Player (w/o Stereo Power Amplifier)
(for A/C System) R 5 Radio and Player (w/o Stereo Power Amplifier)
R 6 Radio and Player (w/ Stereo Power Amplifier)
F 10 Front Tweeter (Speaker) LH R 7 Remote Control Mirror SW
F 11 Front Tweeter (Speaker) RH R 8Rheostat
G 3 Glove Box Light S 6 Seat Heater SW
G 4 Glove Box Light SW S 7 Shift Lock ECU
S 8 Stereo Power Amplifier
H 10 Hazard SW S 9 Stereo Power Amplifier
H 11 Heated Oxygen Sensor (Sub) S 10 Stereo Power Amplifier
H 12 Heater Control SW S 11 Stop Light SW
H 13 Heater Control SW S 16 Sub Heated Oxygen Sensor
(for California)
I 18 Ignition Key Cylinder Light
I 19 Ignition SW T 5 Telltale Light LH
I 20 Integration Relay T 6 Telltale Light RH
T 7 Theft Deterrent ECU
J 1 Junction Connector T 8 TRAC Off SW
J 2 Junction Connector T 9 Traction ECU
T 10 Traction ECU
K 3 Key Interlock Solenoid T 13 Theft Deterrent ECU
K 4 Kick Down SW
U 1 Unlock Warning SW
N 2 Noise Filter

46
POWER SOURCE (Current Flow Chart)*1: (FOR CANADA)
*2: (FOR USA)
A/C Condenser Fan Motor
228
A2 *Page Nos. of
Related Systems
Parts
Code or
Location
CB or Fuse
Location
* These are the page numbers of the first page on which the related system is shown.
The part indicated is located somewhere in the system, not necessarily on the page indicated here.


7.5A HTR
7.5A IGN
7.5A RAD No. 2
7.5A ST
7.5A TURN
10A ECU±B
10A ECU±IG
10A GAUGE
10A MIR±HTR
10A PANEL
10A TAIL
15A CIG
15A SEAT±HTR
15A STOP
20A WIPER
30A DEFOG
30A DOOR
7.5A ALT±S
7.5A DOME
7.5A DRL
7.5A TRAC
15A FOG
15A HAZ±HORN
15A HEAD (LH) *2
15A HEAD (LH±LWR) *1
15A HEAD (LH±UPR) *1
15A HEAD (RH) *2
15A HEAD (RH±LWR) *1
15A HEAD (RH±UPR) *1
20A RAD No. 1
30A ABS No. 2
30A EFI No. 1
30A EFI No. 2
30A FAN
50A HTR
50A MAIN
60A ABS No. 1
60A POWERA3 A4 A6 A8 A9 A12 A14 A18 A19 A20 A22 A23 A24 A29 A30 A33 B1 B2 B4 B6 B7 228 228159
164159 159 228208
228159 159 164 164159
164228 122 210 210 116164
220228 206 206
A/C Single Pressure SW
[A/C Triple Pressure SW]
A/C Magnetic Clutch and
Lock Sensor
ABS Actuator
ABS Relay
A/C Amplifier
ABS ECU
ABS and Traction ECU
ABS Lateral Acceleration
Sensor
Air Inlet Control Servo Motor
Ashtray Illumination
Auto Antenna Control Relay
Auto Antenna Motor
Back±Up Light SW (for M/T)
Brake Fluid Level Warning SW
Blower Motor Control Relay
Buckle SW LH
Buckle SW RH
[LOCATION](1): J/B No. 1 (See page 20)(2): R/B No. 2 (See page 19)(3): R/B No. 4 (See page 23)
20 22
23

51
R9 111
Rear Turn Signal Light LH
[Rear Comb. Light LH]
R10 R11 R12 R15 R16 R17 R18 S3 S6 S7 S8 S9 S11 S12 S13 S14 S15 S16 T1 T3 T4 T5 114 102 116 111 114 102 102 102 203188
208188
20820860
64122
192184210
214210
70
11 4
150
164 82
140
159
174
184192 192 192 192 82 130 164 164 159
Stop Light LH
[Rear Comb. Light LH]
Taillight LH
[Rear Comb. Light LH]
Back±Up Light RH
[Rear Comb. Light RH]
Rear Turn Signal Light RH
[Rear Comb. Light RH]
Stop Light RH
[Rear Comb. Light RH]
Taillight RH
[Rear Comb. Light RH]
Rear Side Marker Light LH
Rear Side Marker Light RH
Rear Wiper Motor and Relay
Remote Control Mirror and
Mirror Heater LH
Remote Control Mirror and
Mirror Heater RH
Rear Window Defogger (+)
Starter
Seat Heater SW
Shift Lock ECU
Stereo Power Amplifier
Stereo Power Amplifier
Stop Light SW
Seat Heater
(for Driver's Seat)
Seat Heater
(for Passenger's Seat)
Seat Heater Relay
(for Driver's Seat)
Seat Heater Relay
(for Passenger's Seat)
Sub Heated Oxygen Sensor
(for California)
Theft Deterrent Horn
Traction Brake Actuator
Traction Pump and Motor
ABS Indicator Light
[Telltale Light LH]
(4): R/B No. 5 (See page 20)
23

52
POWER SOURCE (Current Flow Chart)*1: (FOR CANADA)
*2: (FOR USA)
*Page Nos. of
Related Systems
Parts
Code or
Location
CB or FuseT5 70
82
Location
Malfunction Indicator Lamp
(Check Engine Warning Light)
[Telltale Light LH]
* These are the page numbers of the first page on which the related system is shown.
The part indicated is located somewhere in the system, not necessarily on the page indicated here.


7.5A HTR
7.5A IGN
7.5A RAD No. 2
7.5A ST
7.5A TURN
10A ECU±B
10A ECU±IG
10A GAUGE
10A MIR±HTR
10A PANEL
10A TAIL
15A CIG
15A SEAT±HTR
15A STOP
20A WIPER
30A DEFOG
30A DOOR
7.5A ALT±S
7.5A DOME
7.5A DRL
7.5A TRAC
15A FOG
15A HAZ±HORN
15A HEAD (LH) *2
15A HEAD (LH±LWR) *1
15A HEAD (LH±UPR) *1
15A HEAD (RH) *2
15A HEAD (RH±LWR) *1
15A HEAD (RH±UPR) *1
20A RAD No. 1
30A ABS No. 2
30A EFI No. 1
30A EFI No. 2
30A FAN
50A HTR
50A MAIN
60A ABS No. 1
60A POWERT6
T7
T8T9 T11 T12V1
V2V3
V4 V5 V6 V7 164
22068 118102
11 4194 197
70
122
150
181 82
140
174
220
228 60
64
130122 164 206 206 8270
8270
8270 7070
8270
Telltale Light LH
Charge Warning Light
[Telltale Light RH]
Open Door Warning Light
[Telltale Light RH]
Rear Light Warning Light
[Telltale Light RH]
Seat Belt Warning Light
[Telltale Light RH]
SRS Warning Light
[Telltale Light RH]
Telltale Light RH
Theft Deterrent ECU
TRAC Off SW
Traction ECU
Tension Reducer Solenoid LH
Tension Reducer Solenoid RH
VSV (for ACIS)
VSV (for EGR)
VSV (for EVAP)
VSV (for Exhaust Bypass
Valve)
VSV (for Exhaust Gas
Control Valve)
VSV (for Fuel Pressure Up)
VSV (for Intake Air
Control Valve)
[LOCATION](1): J/B No. 1 (See page 20)(2): R/B No. 2 (See page 19)(3): R/B No. 4 (See page 23)
20 22
23