1997 TOYOTA SUPRA engine

- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-507
735 Author
: Date
:
1997 SUPRA (RM502U)EFI+ (T15-7) - E1 (T15-26)
Pulse generationIG switch ON
EFI- (T15-20) - E1 (T15-26)Pulse generationIG switch ON
ETC+ (T15-8) - E1 (T15-26)Pulse generationIG switch ON
ETC- (T15-21) - E1 (T15-26)Pulse generationIG switch ON
TC (T16-3) - E1 (T15-26)4.5 - 5.5IG switch ON, Engine stops
WA (T16 5) E1 (T15 26)9 - 14IG switch ON, ABS ECU normal conditionWA (T16-5) - E1 (T15-26)0 - 3IG switch ON, ABS ECU abnormal condition

F03385BE6653F03386F03387
ON
IDL1
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-523
751 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
HINT:
The main throttle position sensor signal is transmitted to the throttle control ECU from ECM, so if an error
occurs at the engine side, the throttle control ECU also detects it.
If DTC No. P0120 or P0121 is being output for the engine, troubleshoot the engine first.
1 Is DTC output for the engine?
Check DTC on page DI-147.
YES Repair circuit indicated by the code output.
NO
2 Check voltage between terminal IDL1 of throttle control ECU and body ground.
PREPARATION:
(a) Remove throttle control ECU with connectors still con-
nected.
(b) Disconnect the vacuum hose from the throttle opener,
and apply vacuum to the throttle opener.
(c) Turn ignition switch ON.
CHECK:
Measure voltage between terminal IDL1 of throttle control ECU
and body ground, when the throttle valve is fully closed and fully
open.
OK:
Throttle valve positionVoltage
Fully closed0 - 3 V
Fully open9 - 14 V
OK Go to step 4.
NG

F03378BE6653F03379F03380
ON
IDL2
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-527
755 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
HINT:
The sub-throttle position sensor signal is transmitted to the throttle control ECU from ECM, so if an error
occurs at the engine side, the throttle control ECU also detects it.
If DTC No. P1400 or P1401 is being output for the engine, troubleshoot the engine first.
1 Is DTC output for the engine?
Check DTC on page DI-147.
YES Repair circuit indicated by the code output.
NO
2 Check voltage between terminal IDL2 of throttle control ECU and body ground.
PREPARATION:
(a) Remove throttle control ECU with connectors still con-
nected.
(b) Remove intake air duct.
(c) Disconnect sub-throttle valve motor connector.
(d) Turn ignition switch ON.
CHECK:
Measure voltage between terminal IDL2 of throttle control ECU
and body ground, when the sub-throttle valve is fully closed
and fully open.
OK:
Sub-throttle valve positionVoltage
Fully closed0 - 3 V
Fully open9 - 14 V
OK Go to step 4.
NG
3 Check for open and short in harness and connector between terminal IDL2 of
throttle control ECU and sub-throttle position sensor (See page IN-28).
NG Repair or replace harness or connector.
OK

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

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

F03400
J/B No.1
GAUGE 12
Throttle Control
ECU
WA ABS
Warning Light
Y L
L
L
L ABS ECU
12V
WA5 11
A20
IF2T5
T161E 42
T5
12
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-545
773 Author
: Date
:
1997 SUPRA (RM502U)
DTC 81 ABS Control System Malfunction
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
81Engine speed is 500 rpm or more and ABS warning light is ON
for 12 sec. or more.
Wire harness and connector (WA circuit)

ABS ECU

Throttle control ECU
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check the DTC for the ABS (See page DI-501).
*1 Repair ABS control system according to the
code output.
*2
*1: Output NG code
*2: Malfunction indicator light remains ON
DI4W8-01