Page 977 of 1807
DI-686
- DIAGNOSTICSCRUISE CONTROL SYSTEM
914 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check throttle position sensor circuit
(2JZ-GE: See page SF-42, 2JZ-GTE: See page SF-44).
NG Replace throttle position sensor.
OK
2 Check harness and connector between ECM and throttle position sensor
(See page IN-28).
NG Repair or replace harness or connector.
OK
3 Check harness and connector between cruise control ECU and throttle position
sensor (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU
(See page IN-28).
Page 978 of 1807

N19613
22
1 2
4
3
10 16Cruise Control ECU
1B
I1 S11
S11G-W
B-W
Cruise Control Actuator R/B No.2
Battery
B 2A2
ALT
W-LJ/B No.1
STOP10
C16
L STP-
2 W-L
S11 S11
C16
POWERR-LR-LWStop Light Switch
- DIAGNOSTICSCRUISE CONTROL SYSTEM
DI-687
915 Author: Date:
1997 SUPRA (RM502U)
Stop Light Switch Circuit
CIRCUIT DESCRIPTION
When the brake is on, battery positive voltage normally applies through the STOP fuse and stop light switch
to terminal STP- of the ECU, and the ECU turns the cruise control off.
A fail-safe function is provided so that cancel functions normally, even if there is a malfunction in the stop
light signal circuit.
If the harness connected to terminal STP- has an open circuit, terminal STP- will have battery positive volt-
age and the cruise control will be turned off.
Also, when the brake is on, the magnetic clutch is cut mechanically by the stop light switch, turning the cruise
control off. (See page DI-675 for operation of the magnetic clutch)
WIRING DIAGRAM
DI4XX-01
Page 979 of 1807
Input SignalIndicator Light
Blinking Pattern
Stop Light
switch ON
LightOFF
ONSW OFF
SW ON
DI-688
- DIAGNOSTICSCRUISE CONTROL SYSTEM
916 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check operation of stop light.
CHECK:
Check that stop light comes on when brake pedal is depressed, and turns off when brake pedal is released.
NG Check stop light system.
OK
2 Input signal check.
CHECK:
(a) See input signal check on DI-662.
(b) Check the indicator light when the brake pedal is de-
pressed.
OK:
The indicator light goes off when the brake pedal is
depressed.
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI-671).
NG
Page 980 of 1807
I02722
ON
(-)STP-(+)
- DIAGNOSTICSCRUISE CONTROL SYSTEM
DI-689
917 Author: Date:
1997 SUPRA (RM502U)
3 Check voltage between terminal STP- of cruise control ECU connector and body
ground.
PREPARATION:
Remove cruise control ECU with connectors still connected.
CHECK:
(a) Turn ignition switch ON.
(b) Measure voltage between terminal STP-of cruise control
ECU connector and body ground, when the brake pedal
is depressed and released.
OK:
Depressed10 - 14 V
ReleasedBelow 1 V
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI-671).
NG
4 Check for open in harness and connectors between terminal STP- of cruise con-
trol ECU and stop light switch (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU
(See page IN-28).
Page 981 of 1807

N19614
ECM
E10
E9IJ2
IJ2C16
C16
E2
E2 12
9
8
2229 11
10Cruise Control ECU
OD
ECT BR-B*1LG-B
LG-B*1(A/T)
R-L
(A/T) OD1
S2
*1: 2JZ-GTE Engine
*2: 2JZ-GE Engine R-L
(A/T)R-L
(A/T)
Electronically Controlled Transmission Solenoid*1
*2
S2 DI-690
- DIAGNOSTICSCRUISE CONTROL SYSTEM
918 Author: Date:
1997 SUPRA (RM502U)
Electronically Controlled Transmission Communication Circuit
CIRCUIT DESCRIPTION
When driving uphill under cruise control, in order to reduce shifting due to ON-OFF overdrive operation and
to provide smooth driving, when down shifting in the electronically controlled transmission occurs, a signal
to prevent upshift until the end of the uphill slope is sent from the cruise control ECU to the electronically
controlled transmission.
Terminal ECM of the cruise control ECU detects the shift change signal (output to electronically controlled
transmission No.2 solenoid) from the electronically controlled transmission.
If vehicle speed down, also when terminal electronically controlled transmission of the cruise control ECU
receive down shifting signal, it sends a signal from terminal OD to ECM to cut overdrive until the end of the
uphill slope, and the gear shifts are reduced and gear shift points in the electronically controlled transmission
are changed.
WIRING DIAGRAM
DI4XY-01
Page 982 of 1807
I02724
ON
(-)
OD (+)
- DIAGNOSTICSCRUISE CONTROL SYSTEM
DI-691
919 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check operation of overdrive.
PREPARATION:
Test drive after engine warms up.
CHECK:
Check that overdrive ON e OFF occurs with operation of OD switch ON e OFF.
NG Check and repair electronically controlled
transmission (See page DI-371).
OK
2 Check voltage between terminal OD of harness side connector of cruise control
ECU and body ground.
PREPARATION:
Remove cruise control ECU with connector still connected.
CHECK:
(a) Disconnect cruise control ECU connector.
(b) Turn ignition switch ON.
(c) Measure voltage between terminal OD of harness side
connector of cruise control ECU and body ground.
OK:
Voltage: 10 - 14 V
NG Go to step 5.
OK
Page 983 of 1807
N19837
(-)ECT (+)
DI-692
- DIAGNOSTICSCRUISE CONTROL SYSTEM
920 Author: Date:
1997 SUPRA (RM502U)
3 Check voltage between terminal ECT of cruise control ECU connector and body
ground (On test drive).
PREPARATION:
(a) Connect cruise control ECU connector.
(b) Test drive after engine warms up.
CHECK:
Check voltage between terminal ECT of cruise control ECU
connector and body ground when OD switch is ON and OFF.
OK:
OD switch positionVoltage
ON8 - 14 V
OFFBelow 0.5 V
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI-671).
NG
4 Check harness and connector between terminal ECT of cruise control ECU and
electronically controlled transmission solenoid (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU.
Page 984 of 1807
- DIAGNOSTICSCRUISE CONTROL SYSTEM
DI-693
921 Author: Date:
1997 SUPRA (RM502U)
5 Check harness and connector between terminal OD of cruise control ECU and
terminal OD1 of ECM (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU
(See page IN-28).