Page 793 of 1807
R01346
Normal Code
2 sec.
0.25
sec.
0.25
sec.
ON
OFF
Code 11 and 21
ON
OFF0.5 sec.
2.5 sec. 4.5 sec.1.5
sec. 0.5 sec.
Code 11Code 21
F03366
ECU-B
J/B No.1 DI-502
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
730 Author: Date:
1997 SUPRA (RM502U)
(3) Read the DTC from the TRAC OFF indicator light on
the combination meter.
HINT:
If no code appears, inspect the diagnostic circuit or TRAC
OFF indicator light circuit (See page DI-553 or
DI-547).
As an example, the blinking patterns for normal code and
codes 11 and 21 are shown on the left.
(4) Codes are explained in the code table on page
DI-503.
(5) After completing the check, disconnect terminals Tc
and E1, and turn off the display.
If 2 or more malfunctions are indicated at the same time, the
lowest numbered DTC will be displayed 1st.
(c) Clear the DTC.
(1) Remove the ECU-B fuse from the J/B No.1 for 10
sec. or more.
(2) Install the ECU-B fuse.
(3) Confirm that the TRAC OFF indicator light shows
the normal code.
Page 794 of 1807

DI4VS-01
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-503
731 Author: Date:
1997 SUPRA (RM502U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Using SST 09843-18020, connect the terminals Tc and E
1.
If a malfunction code is displayed during the DTC check, check the circuit listed for that code. For details
of each code, turn to the page referred to under the ºSee pageº for the respective ºDTC No.º in the DTC chart.
DTC No.
(See Page)Detection ItemTrouble Area
11
(DI-509)Throttle control relay circuit open
Throttle control relay
TRAC fuse
Wire harness and connector (throttle control relay circuit)
Throttle control ECU
12
(DI-509)Throttle control relay circuit short
Throttle control relay
Wire harness and connector (throttle control relay circuit)
Throttle control ECU
21
(DI-513)Sub-throttle valve motor circuit open or short
Sub-throttle valve motor
Wire harness and connector (sub-throttle valve motor and
E01 circuit)
Throttle control ECU
22
(DI-513)Sub-throttle valve motor malfunction
Sub-throttle valve motor
Sub-throttle valve
Sub-throttle position sensor
Wire harness and connector (E1 circuit)
Throttle control ECU
23
(DI-516)Throttle body malfunction
Sub-throttle valve
Sub-throttle position sensor
Throttle control ECU
24
(DI-519)Sub-throttle position sensor leakage/sub-throttle valve stuck
Sub-throttle valve
Sub-throttle position sensor
Wire harness and connector (E1 circuit)
Throttle control ECU
31
(DI-522)Throttle position sensor signal malfunction
Throttle position sensor
Wire harness and connector (throttle position senor and E1
circuit)
Throttle control ECU
32
(DI-526)Sub-throttle position sensor signal malfunction
Sub-throttle position sensor
Sub-throttle valve motor
Sub-throttle valve
Wire harness and connector (sub-throttle position senor and
E1 circuit)
Throttle control ECU
41
(DI-530)Engine revolution signal open or short
Wire harness and connector (NE circuit)
ECM
Throttle control ECU
42
(DI-532)ECM malfunction
Wire harness and connector (EFIF circuit)
ECM
Throttle control ECU
43
(DI-534)ECM communication circuit malfunction
Wire harness and connector (EFI+ and EFI- circuit)
ECM
Throttle control ECU
51
(DI-535)Power source voltage down
(sub-throttle valve in a bad condition)Wire harness and connector (+B and E01 circuit)
Throttle control ECU
Page 795 of 1807
DI-504
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
732 Author: Date:
1997 SUPRA (RM502U)52
(DI-535)
Power source voltage down
Battery
IC regulator
Wire harness and connector (+B and E01 circuit)
Throttle control ECU
61
(DI-538)Right front speed sensor circuit
62
(DI-538)Left front speed sensor circuitRight front, left front, right rear and left rear speed sensor
Wire harness and connector
(FRO, FLO, RRO and RLO
63
(DI-538)Right rear speed sensor circuit
Wire harness and connector (FRO, FLO, RRO and RLO
circuit)
Throttle control ECU
64
(DI-538)Left rear speed sensor circuit
71
(DI-542)Emergency fuel cut (sub-throttle motor circuit malfunction)Sub-throttle valve motor
S b th ttl l72
(DI-542)Emergency fuel cut
Sub-throttle valve
Throttle control ECU
81
(DI-545)ABS ECU malfunction
Wire harness and connector (WA circuit)
ABS ECU
Throttle control ECU
Always ONThrottle control ECU malfunction
TRAC OFF switch ONThrottle control ECU
Page 796 of 1807
DI4VT-01
W02272
Rear Speed Sensor Rotor SLIP Indicator Light
TRAC OFF Indicator Light
SNOW Indicator Light
Throttle Control Relay
(TRAC Solenoid Relay)TRAC OFF
Switch SNOW Mode
Switch
ABS ECU
ECM Throttle Control ECU
DLC1
Throttle Position Sensor
Sub-throttle
Position Sensor
Front Speed Sensor Rotor
Sub-throttle Valve MotorFront Speed SensorFront Speed Sensor RotorRear Speed Sensor
DLC2
Front Speed Sensor
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-505
733 Author: Date:
1997 SUPRA (RM502U)
PARTS LOCATION
Page 797 of 1807

DI7HK-01
R00463
13 12 11
26 25 24 23 22 21 20 19 18 17 16 15 14 16 15 14 13 12 11 10 91 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 9 10 Throttle Contrl ECU
T15T16
DI-506
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
734 Author: Date:
1997 SUPRA (RM502U)
TERMINALS OF ECU
Symbols (Terminal No.)STD Voltage (V)Condition
BATT (T16-1) - E1 (T15-26)9 - 14Always
+B (T16-9) - E1 (T15-26)9 - 14IG switch ON, Engine stops
EFIB (T15-1) - E1 (T15-26)9 - 14IG switch ON, Engine stops
IDL1 (T15 4) E1 (T15 26)0 - 3IG switch ON, Throttle valve fully closedIDL1 (T15-4) - E1 (T15-26)9 - 14IG switch ON, Throttle valve fully open
VTA1 (T15 6) E1 (T15 26)0.3 - 0.8IG switch ON, Throttle valve fully closedVTA1 (T15-6) - E1 (T15-26)3.2 - 4.9IG switch ON, Throttle valve fully open
IDL2 (T15 3) E1 (T15 26)0 - 3Engine running, Sub-throttle valve fully closedIDL2 (T15-3) - E1 (T15-26)9 - 14Engine running, Sub-throttle valve fully open
VTA2 (T15 19) E1 (T15 26)0.3 - 0.8Engine running, Sub-throttle valve fully closedVTA2 (T15-19) - E1 (T15-26)3.2 - 4.9Engine running, Sub-throttle valve fully open
FRO (T16-16) - E1 (T15-26)Pulse generationVehicle driving at about 30 km/h (19 mph)
FLO (T16-8) - E1 (T15-26)Pulse generationVehicle driving at about 30 km/h (19 mph)
RRO (T16-15) - E1 (T15-26)Pulse generationVehicle driving at about 30 km/h (19 mph)
RLO (T16-7) - E1 (T15-26)Pulse generationVehicle driving at about 30 km/h (19 mph)
WT (T16 10) E1 (T15 26)0 - 3IG switch ON, TRAC OFF indicator light ONWT (T16-10) - E1 (T15-26)9 - 14IG switch ON, TRAC OFF indicator light OFF
IND (T16 2) E1 (T15 26)0 - 3IG switch ON, SLIP indicator light ONIND (T16-2) - E1 (T15-26)9 - 14IG switch ON, SLIP indicator light OFF
CSW (T16 6) E1 (T15 26)0 - 3IG switch ON, TRAC OFF switch holded on pushingCSW (T16-6) - E1 (T15-26)9 - 14IG switch ON, TRAC OFF switch released
RLY+ (T16-4) - RLY- (T16-12)9 - 14IG switch ON
SIND (T16 11) E1 (T15 26)0 - 3IG switch ON, SNOW indicator light ONSIND (T16-11) - E1 (T15-26)9 - 14IG switch ON, SNOW indicator light OFF
SNOW (T16 14) E1 (T15 26)0 - 3IG switch ON, SNOW mode switch holded on pushingSNOW (T16-14) - E1 (T15-26)9 - 14IG switch ON, SNOW mode switch released
A (T15-12) - E01 (T15-13)Pulse generationEngine running, Throttle valve fully closed
A (T15-11) - E01 (T15-13)Pulse generationEngine running, Throttle valve fully closed
B (T15-25) - E01 (T15-13)Pulse generationEngine running, Throttle valve fully closed
B (T15-24) - E01 (T15-13)Pulse generationEngine running, Throttle valve fully closed
NE (T15-16) - E1 (T15-26)Pulse generationIdling
FAIL (T15 9) E1 (T15 26)Pulse generationIG switch ON (normal condition)FAIL (T15-9) - E1 (T15-26)9 - 14IG switch ON (abnormal condition)
EFIF (T15 17) E1 (T15 26)0 - 2IG switch ON, ECM normal conditionEFIF (T15-17) - E1 (T15-26)4.5 - 5.5IG switch ON, ECM abnormal condition
Page 798 of 1807
- 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
Page 799 of 1807

DI4VV-01
DI-508
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
736 Author: Date:
1997 SUPRA (RM502U)
PROBLEM SYMPTOMS TABLE
If a normal code is displayed during the DTC check but the problem still occurs, check the circuits for each
problem symptom in the order given in the table below and proceed to the relevant troubleshooting page.
SymptomInspection CircuitSee page
TRAC does not operate.
Only when inspection circuits for each problem symptom are all normal and the
problem is still occurring,replace the throttle control ECU.
1. Check the DTC, reconfirming that the normal code is output.
2. Power source circuit.
3. Speed sensor circuit.
DI-501
DI-535
DI-538
SLIP indicator light
abnormal.SLIP indicator light circuit.DI-550
SNOW indicator light
abnormal.1. SNOW indicator light circuit.
2. SNOW made switch circuit.DI-551
DI-551
TRAC OFF indicator light
abnormal.
Only when inspection circuits for each problem symptom are all normal and the
problem is still occurring,replace the throttle control ECU.
1. TRAC OFF indicator light circuit.
2. TRAC OFF switch circuit.
DI-547
DI-547
DTC check cannot be done.
Only when inspection circuits for each problem symptom are all normal and the
problem is still occurring,replace the throttle control ECU.
1. TRAC OFF indicator light circuit.
2. Tc terminal circuit.
DI-547
DI-553
Page 800 of 1807
DI4VW-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 L-R
BR-B
B2
1
2A5
4
2
13
IB5
T16
T15
EC 51
65
5
IB5
IB5T16
T16
TRAC
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-509
737 Author: Date:
1997 SUPRA (RM502U)
CIRCUIT INSPECTION
DTC 11, 12 Throttle Control Relay Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
11Instead of throttle control relay is ON, voltage at +B of ECU
terminal does not output 4 V or more for 1 sec. or more.
Throttle control relay
TRAC fuse
Wire harness and connector (throttle control relay circuit)
Throttle control ECU
12Instead of throttle control relay is OFF, voltage at +B of ECU
terminal outputs 4 V or more for 2 sec. or more.Throttle control relay
Wire harness and connector (throttle control relay circuit)
Throttle control ECU
WIRING DIAGRAM