1996 TOYOTA T100 engine

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3 4
− DIAGNOSTICSCRUISE CONTROL SYSTEM
DI−433
1996 TOYOTA T100 (RM449U)
3 Check control switch.
PREPARATION:
(a) Remove steering wheel center pad.
(b) Disconnect the control switch connector.
CHECK:
Measure resistance between terminals 3 and 4 of control switch
connector when control switch is operated.
Switch positionResistance (Ω)
Neutral∞ (No continuity)
RES/ACC50 − 80
SET/COAST180 − 220
CANCEL400 − 440
NG Replace control switch.
OK
4Check harness and connector between cruise control ECU and cruise control switch,
cruise control switch and body ground (See page
IN−16).
NG Repair or replace harness or connector.
OK
5 Input signal check (See step 1).
OK Wait and see.
NG
Check and replace cruise control ECU (See
page IN−26).

Downloaded from www.Manualslib.com manuals search engine I22687
DI−434
− DIAGNOSTICSCRUISE CONTROL SYSTEM
1996 TOYOTA T100 (RM449U)
Stop Light Switch Circuit
CIRCUIT DESCRIPTION
When the brake pedal is depressed, the stop light switch sends a signal to the ECU. When the ECU receives
this signal, it cancels the cruise control.
A fail−safe function is provided so that the cancel functions normally, even if there is a malfunction in the stop
light signal circuit.
The cancel conditions are: Battery positive voltage at terminal STP−
When the brake is ON, battery positive voltage is normally applied through the STOP fuse and stop light
switch to terminal STP− of the ECU, and the ECU turns the cruise control OFF.
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 circuit is cut mechanically by the stop light switch, turning
the cruise control OFF (See page DI−422 for operation of the magnetic clutch).
WIRING DIAGRAM
DI355−02

Downloaded from www.Manualslib.com manuals search engine Input SignalIndicator Light
Blinking Pattern
Stop Light
switch ON
LightON
OFFSW OFF
SW ON
− DIAGNOSTICSCRUISE CONTROL SYSTEM
DI−435
1996 TOYOTA T100 (RM449U)
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 (See page BE−30).
OK
2 Input signal check.
CHECK:
(a) See input signal check on DI−410.
(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 in
problem symptoms table (See page DI−419).
NG

Downloaded from www.Manualslib.com manuals search engine AB0119
I00015I00024
ON
STP−
(−) (+)
DI−436
− DIAGNOSTICSCRUISE CONTROL SYSTEM
1996 TOYOTA T100 (RM449U)
3 Check voltage between terminal STP− of cruise control ECU connector and
body ground.
PREPARATION:
(a) Remove the ECU with connectors still connected.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminal STP− of cruise control ECU
connector and body ground, when the brake pedal is de-
pressed and released.
OK:
Depressed10 − 16 V
ReleasedBelow 1 V
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI−419).
NG
4 Check for open in harness and connectors between terminal STP− of cruise con-
trol ECU and stop light switch (See page IN−16).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU (See
page IN−26).

Downloaded from www.Manualslib.com manuals search engine I22676
− DIAGNOSTICSCRUISE CONTROL SYSTEM
DI−437
1996 TOYOTA T100 (RM449U)
Idle Switch Circuit
CIRCUIT DESCRIPTION
When the idle switch is turned ON, a signal is sent to the ECU. The ECU uses this signal to correct the dis-
crepancy between the throttle valve position and the actuator position sensor value to enable accurate
cruise control at the set speed. If the idle switch is malfunctioning, problem symptoms also occur in the en-
gine, so also inspect the engine.
WIRING DIAGRAM
DI356−02

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DI−438
− DIAGNOSTICSCRUISE CONTROL SYSTEM
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check voltage between terminal IDL of cruise control ECU connector and body
ground.
PREPARATION:
(a) Remove the ECU with connector still connected.
(b) Disconnect the ECM and ABS ECU connectors.
(c) Turn ignition switch ON.
CHECK:
Measure voltage between terminal IDL of ECU connector and
body ground when the throttle valve is fully closed and fully
opened.
OK:
Throttle valve positionVoltage
Fully opened10 − 16 V
Fully closedBelow 1 V
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI−419).
NG
2 Check harness and connector between ECM and throttle position sensor (See
page IN−16).
NG Repair or replace harness or connector.
OK
3 Check throttle position sensor circuit.
(3RZ−FE: See page MF−25)
(5VZ−FE: See page SF−31)
NG Replace throttle position sensor.
OK

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Throttle Position Sensor
1
2
− DIAGNOSTICSCRUISE CONTROL SYSTEM
DI−439
1996 TOYOTA T100 (RM449U)
4 Check throttle position sensor.
PREPARATION:
Disconnect the throttle position sensor connector.
CHECK:
Measure resistance between terminals 1 and 2 of throttle posi-
tion sensor connector when the throttle valve is fully closed and
fully opened.
OK:
Throttle valve positionResistance
Fully opened1 MΩ or higher
Fully closedBelow 500 Ω
NG Replace throttle position sensor.
OK
5 Check for open and short in harness and connector between cruise control ECU
and throttle position sensor, throttle position sensor and body ground (See page
IN−16).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU (See
page IN−26).

Downloaded from www.Manualslib.com manuals search engine I22685
DI−440
− DIAGNOSTICSCRUISE CONTROL SYSTEM
1996 TOYOTA T100 (RM449U)
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 up hill slope is sent from the cruise control ECU to the electronically
controlled transmission.
Terminal ECT of the cruise control ECU detects the shift change signal (output to electronically controlled
transmission No. 2 solenoid) from the ECM.
If vehicle speed down, also when terminal ECT of the cruise control ECU receives 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
DI357−02