TOYOTA SUPRA 1997 Service Repair Manual

BR5440
Throttle Control ECU
5V
NE
T1516
P-L 38
E10 NEO ECM DI-530
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
758 Author
: Date
:
1997 SUPRA (RM502U)
DTC 41 NE Signal Circuit
CIRCUIT DESCRIPTION
The throttle control ECU receives engine speed signals (NE signals) from the ECM.
DTC No.DTC Detecting ConditionTrouble Area
41While engine is running, throttle control ECU detected 0 rpm
signal for 0.8 sec. or more.
Wire harness and connector (NE circuit)

ECM

Throttle control ECU
WIRING DIAGRAM
DI4W2-01

BE6653F03391F03392
ON
NE
(Reference)
3 - 6 V
Below 1V
3 ms. 3 ms.
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-531
759 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
HINT:
If DTC No. P0335 is being output for the engine, troubleshoot the engine first.
1 Check for open and short in harness and connector between terminal NE of
throttle control ECU and terminal NEO of ECM (See page IN-28).
NG Repair or replace harness or connector.
OK
2 Check voltage between terminal NE of throttle control ECU and body ground.
PREPARATION:
(a) Remove throttle control ECU with connectors still con-
nected.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminal NE of throttle control ECU
and body ground for the engine conditions below.
OK:
Engine conditionVoltage
OFF (IG ON)3 - 6 V or below 1 V
ON (Idling)2 - 3 V (Pulse)
NG Check and replace ECM.
OK
Check and replace throttle control ECU.

F03393
Trottle Conrol ECU
5V
5V EFIF
EFI+
EFI-
GE11 P
B
W
(Shielded) ECM
EFIF
EFI+
EFI-
T15
T1517
7
20
15
T15 67
E9
27
E10
26
E10 T15
DI-532
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
760 Author
: Date
:
1997 SUPRA (RM502U)
DTC 42 Engine Control System Malfunction
CIRCUIT DESCRIPTION
If trouble in the engine control system causes the malfunction indicator light to light up, this information is
transmitted from the ECM to the throttle control ECU. Then throttle control ECU may prohibit TRAC control
as a result.
DTC No.DTC Detecting ConditionTrouble Area
42ECM detected malfunction signal ON (output voltage at termi-
nal EFIF is 4.5 V or more, or 5.5 V or less for 1 sec. or more).
Wire harness and connector (EFIF circuit)

ECM

Throttle control ECU
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check the DTC for the engine (See page DI-147).
*1 Repair engine control system according to the
code output.
*2
*1: Output NG code
*2: Malfunction indicator light remains ON
DI4W3-01

- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-533
761 Author
: Date
:
1997 SUPRA (RM502U)
2 Check for open and short in harness and connector between terminal EFIF of
throttle control ECU and terminal EFIF of ECM (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace throttle control ECU.

F03393
Trottle Conrol ECU
5V
5V EFIF
EFI+
EFI-
GE11 P
B
W
(Shielded) ECM
EFIF
EFI+
EFI-
T15
T1517
7
20
15
T15 67
E9
27
E10
26
E10T15
DI-534
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
762 Author
: Date
:
1997 SUPRA (RM502U)
DTC 43 ECM Communication Circuit Malfunction
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
43ECM normal communication data is not received for 5 sec. or
more.
Wire harness and connector (EFI+ and EFI- circuit)

ECM

Throttle control ECU
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check for open and short in harness and connector between terminals EFI+ and
EFI- of throttle control ECU and ECM (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace ECM or throttle control
ECU.
DI4W4-01

F03368
Throttle Control
ECU R/B No.5
Throttle Control Relay
(TRAC Solenoid Relay)
R/B
No.2
Battery+B
RLY-
RLY+
E01 9
12
4
13
BR L-B BR-BL-R 14
11
12
L-B L-Y
TRAC
L-R
BR-B
B
2
12A2
15
4 3
51
65
5
T15
EC IB5 T16T16T16
IB5 IB5
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-535
763 Author
: Date
:
1997 SUPRA (RM502U)
DTC 51, 52 Power Source Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
51In case power source voltage comes down, sub-throttle valve
angle difference occurs.
Wire harness and connector (+B and E01 circuit)

Throttle control ECU
52Engine speed is 500 rpm or more and throttle relay is ON and
ECU terminal +B voltage is less than 8 V for 10 sec. or more.

Battery

IC regulator

Wire harness and connector (+B and E01 circuit)

Throttle control ECU
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check battery positive voltage.
OK:
Voltage: 10 - 14 V
NG Check and repair the charging system.
OK
DI4W5-01

BE6653F03395F03396
ON
E01
DI-536
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
764 Author
: Date
:
1997 SUPRA (RM502U)
2 Check for open and short in harness and connector between terminal +B of
throttle control ECU and throttle control relay (See page IN-28).
NG Repair or replace harness or connector.
OK
3 Check voltage between terminals +B and E01 of throttle control ECU connector.
PREPARATION:
(a) Remove throttle control ECU with connectors still con-
nected.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals +B and E01 of throttle con-
trol ECU connector.
OK:
Voltage: 9 - 14 V
OK Check and replace throttle control ECU.
NG

BE6653F03397F03398
LOCK
E01
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-537
765 Author
: Date
:
1997 SUPRA (RM502U)
4 Check continuity between terminal E01 of throttle control ECU connector and
body ground.
CHECK:
Measure resistance between terminal E01 of throttle control
ECU connector and body ground.
OK:
Resistance: 1 W or less
NG Repair or replace harness or connector.
OK
Check for open in harness and connector between throttle control ECU and battery
(See page IN-28).

BR3583
BR3582F00010
Speed Sensor
High Speed Rotor
+V
-VLow SpeedTo ECU Magnet
CoilNS
DI-538
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
766 Author
: Date
:
1997 SUPRA (RM502U)
DTC 61, 62, 63, 64 Speed Sensor Circuit
CIRCUIT DESCRIPTION
The speed sensor detects the wheel speed and sends the ap-
propriate signals to the ECU. These signals are used to control
both the ABS and TRAC control systems. The front and rear ro-
tors each have 48 serrations.
When the rotors rotate, the magnetic field emitted by the perma-
nent magnet in the speed sensor generates an AC voltage.
Since the frequency of this AC voltage changes in direct propor-
tion to the speed of the rotor, the frequency is used by the ECU
to detect the speed of each wheel.
DTC No.DTC Detecting ConditionTrouble Area
61,62,63,64
When the brake switch is OFF, one of the symmetrical wheels'
speed becomes one eight or less of the slowest speed of other
3 wheels continuously for 10 sec. or more.
Right front, left front, right rear and left rear speed sensor

Wire harness and connector (FRO, FLO, RRO and RLO
circuit)

Throttle control ECU
HINT:
DTC No.61 is for the right front speed sensor.
DTC No.62 is for the left front speed sensor.
DTC No.63 is for the right rear speed sensor.
DTC No.64 is for the left rear speed sensor.
DI4W6-01

BR5402
Throttle Control ECU
12V
FRO
FLO
RRO
RLO LG-B
O
Y-B
GR-R
Speed
Sensor FRO
FLO
RRO
RLO ABS ECU
16
T16
8
15
7 7
20
A20
A20
A206
9 A20T16
T16
T16
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-539
767 Author
: Date
:
1997 SUPRA (RM502U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If the DTC is output from the ABS warning light, troubleshoot the ABS first.
1 Check for open and short in harness and connector between terminals FRO,
FLO, RRO, RLO of ABS ECU and throttle control ECU (See page IN-28).
NG Repair or replace harness or connector.
OK