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 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 838 of 1807
F03403
Throttle Control ECU
WT
12V
CSW
T16T16
6 10
LG-R LG-R
IF22
TRAC OFF Switch
(TRAC Control Switch)
LG
4 6 W-B
IG IEW-B W-BLG-R
13 OPA DLC2 J/B No.1
GAUGE
1E12
Y
T52TRAC OFF
Indicator
T58
LG-R
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-547
775 Author: Date:
1997 SUPRA (RM502U)
TRAC OFF Indicator Light, TRAC OFF Switch Circuit
CIRCUIT DESCRIPTION
This is the TRAC control main switch. When the TRAC OFF switch is pushed on, TRAC control goes off and
the TRAC OFF indicator lights up. This indicator blinks for warnings when the trouble occurs and for display-
ing DTC.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check DTC.
Check DTC on page DI-501.
YES Repair circuit indicated by the code output.
NO
DI4W9-01
Page 844 of 1807
F03408
Throttle Control ECU
12V
Tc
R R
R P-B DLC1
Tc E1 BR
BR
BR
BRDLC2
E1Tc
3 11
21
11 3
18
ED3
4
IJ1II1
IF1
T16 P-B
S-17-1F02201F03525
DLC2DLC1
E
1
TcE1
Tc
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-553
781 Author: Date:
1997 SUPRA (RM502U)
Tc Terminal Circuit
CIRCUIT DESCRIPTION
By connecting terminals Tc and E1 of DLC1 or DLC2, the ECU displays the DTC by blinking the TRAC OFF
indicator light.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check voltage between terminals Tc and E1 of DLC2 or DLC1.
PREPARATION:
Turn ignition switch ON.
CHECK:
Measure voltage between terminals Tc and E1 of DLC2 or
DLC1.
OK:
Voltage: 10 - 14 V
OK Proceed to next circuit inspection shown on
problem symptoms chart (See page DI-508).
NG
DI4WC-01
Page 851 of 1807

DI4WG-01
DI-560
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
788 Author: Date:
1997 SUPRA (RM502U)
DIAGNOSTIC TROUBLE CODE CHART
DTC No.
(See Page)Detection ItemTrouble AreaSRS
Warning Light
(N l)System normal-OFF(Normal)
(DI-595)Source voltage dropBattery
Airbag sensor assemblyON
11
(DI-564)
Short in squib circuit (to ground)Steering wheel pad (D squib)
Front passenger airbag assembly (P squib)
Spiral cable
Airbag sensor assembly
Wire harness
ON
12
(DI-571)
Short in squib circuit (to B+)Steering wheel pad (D squib)
Front passenger airbag assembly (P squib)
Spiral cable
Airbag sensor assembly
Wire harness
ON
13
(DI-577)
Short in D squib circuitSteering wheel pad (D squib)
Spiral cable
Airbag sensor assembly
Wire harness
ON
14
(DI-582)
Open in D squib circuitSteering wheel pad (D squib)
Spiral cable
Airbag sensor assembly
Wire harness
ON
31
(DI-586)Airbag sensor assembly malfunctionAirbag sensor assemblyON
53
(DI-588)Short in P squib circuitFront passenger airbag assembly (P squib)
Airbag sensor assembly
Wire harness
ON
54
(DI-592)Open in P squib circuitFront passenger airbag assembly (P squib)
Airbag sensor assembly
Wire harness
ON
HINT:
When the SRS warning light remains lit up and the DTC is the normal code, this means a source voltage
drop.
This malfunction is not stored in memory by the airbag sensor assembly and if the power source volt-
age returns to normal, after approx. 10 seconds the SRS warning light will automatically go out.
When 2 or more codes are indicated, the codes will be displayed in numeral order starting from the
lowest numbered code.
If a code not listed on the chart is displayed, the airbag sensor assembly is faulty.
Page 854 of 1807
DI4WJ-01
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI-563
791 Author: Date:
1997 SUPRA (RM502U)
PROBLEM SYMPTOMS TABLE
Proceed with troubleshooting of each circuit in the table below.
Problem SymptomInspection ItemPage
WIth the ignition switch at ACC or ON, the SRS warning light
sometimes lights up after approx. 6 seconds have elapsed.
SRS warning light lights up even when ignition switch is in the
LOCK position.
SRS warning light system malfunction (Always lit up when
ignition switch is in LOCK position.)DI-598
WIth the ignition switch at ACC or ON, the SRS warning light
does not light up.SRS warning light system malfunction (Does not light up
when ignition switch is turned to ACC or ON.)DI-600
DTC not displayed.
SRS warning light is always lit up with a DTC check procedure.
DTC displayed without Tc and E
1 terminal connection.
Tc terminal circuitDI-603
Page 877 of 1807

AB0119
W02766H00041
ONAirbag Sensor Assembly
ACC
IG2 (-)
(+)
DI-586
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
814 Author: Date:
1997 SUPRA (RM502U)
DTC 31 Airbag Sensor Assembly Malfunction
CIRCUIT DESCRIPTION
The airbag sensor assembly consists of a airbag sensor, safing sensor, drive circuit, diagnosis circuit and
ignition control, etc.
It receives signals from the airbag sensors, judges whether or not the SRS must be activated, and diagnosis
system malfunction.
DTC 31 is recorded when occurrence of a malfunction in the airbag sensor assembly is detected.
DTC No.DTC Detecting ConditionTrouble Area
31Airbag sensor assembly malfunction.Airbag sensor assembly
INSPECTION PROCEDURES
HINT:
When a malfunction code other than code 31 is displayed at the same time, first repair the malfunction indi-
cated by the malfunction code other than code 31.
1 Preparation (See step 1 on page DI-595).
2 Check voltage at IG2 and ACC of airbag sensor assembly.
PREPARATION:
Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals IG2 and ACC of airbag
sensor assembly and body ground.
OK:
Voltage: Below 16 V
NG Check battery and charging system.
(See charging system section)
OK
DI4WO-01
Page 886 of 1807

W00786
Relay Block No.2 Junction Block No.1Airbag Sensor
Assembly
2
21B 1J1J
1J1G 1G6
10 3 8
3
G 4
4
W ALT
AM2
Battery IB1 4
Ignition SwitchJunction Block No.1ACC 16
15
AM16 B-W
72
W-RG-R
B-O
IG2 W
22
2A
Relay Block No.2
W
B
1W-RCIG
IGN
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI-595
823 Author: Date:
1997 SUPRA (RM502U)
DTC Normal Source Voltage Drop
CIRCUIT DESCRIPTION
The SRS is equipped with a voltage-increase circuit (DC-DC converter) in the airbag sensor assembly in
case the source voltage drops.
When the battery voltage drops, the voltage-increase circuit (DC-DC converter)functions to increase the
voltage of the SRS to normal voltage.
The diagnosis system malfunction display for this circuit is different to other circuits-when the SRS warning
light remains lit up and the DTC is a normal code, source voltage drop is indicated.
Malfunction in this circuit is not recorded in the airbag sensor assembly, and the source voltage returns to
normal, the SRS warning light automatically goes off.
DTC No.DTC Detecting ConditionTrouble Area
NormalSource voltage drop.Battery
Airbag sensor assembly
WIRING DIAGRAM
DI4WR-01