TOYOTA T100 1996 Factory Service Manual

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− 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).

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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

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I00012I00025
ON
OD
(−) (+)
− DIAGNOSTICSCRUISE CONTROL SYSTEM
DI−441
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check operation of overdrive.
PREPARATION:
Test drive after engine warms up.
CHECK:
Check that overdrive ON ↔ OFF occurs with operation of OD switch ON−OFF.
NG Check and repair electronically controlled
transmission (See page DI−311).
OK
2 Check voltage between terminal OD of harness side connector of cruise control
ECU and body ground.
PREPARATION:
(a) Remove the ECU with connector still connected.
(b) Turn ignition switch ON.
(c) Disconnect the ECU connector.
CHECK:
Measure voltage between terminal OD of ECU connector on
the harness side and body ground.
OK:
Voltage: 10 − 16 V
NG Go to step 5.
OK

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ECT
(−) (+)
DI−442
− DIAGNOSTICSCRUISE CONTROL SYSTEM
1996 TOYOTA T100 (RM449U)
3 Check voltage between terminal ECT of cruise control ECU connector and body
ground (On test drive).
PREPARATION:
(a) Connect the ECU connector.
(b) Test drive after engine warms up.
CHECK:
Check voltage between terminal ECT of ECU connector and
body ground when OD switch is ON and OFF.
OK:
OD switch positionVoltage
ONBelow 1 V
OFF10 − 16 V
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI−419).
NG
4 Check harness and connector between terminal ECT of cruise control ECU and
electronically controlled transmission solenoid (See page IN−16).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU.(See
page IN−26)
5 Check harness and connector between terminal OD of cruise control ECU and
terminal OD1 of ECM (See page IN−16).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU (See
page IN−26).

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− DIAGNOSTICSCRUISE CONTROL SYSTEM
DI−443
1996 TOYOTA T100 (RM449U)
Park/Neutral Position Switch Circuit
CIRCUIT DESCRIPTION
When the shift position is in except D position, a signal is sent from the park/neutral position switch to the
ECU. When this signal is input during cruise control driving, the ECU cancels the cruise control.
WIRING DIAGRAM
DI358−02

Downloaded from www.Manualslib.com manuals search engine Input SignalIndicator Light
Blinking Pattern
Turn PNP switch
OFF (Shift to
except D position)LightON
OFFSW ON
SW OFF
DI−444
− DIAGNOSTICSCRUISE CONTROL SYSTEM
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check starter operation.
CHECK:
Check that the starter operates normally and that the engine starts.
NG Proceed to engine troubleshooting.
(3RZ−FE: See page DI−1)
(5VZ−FE: See page DI−127)
OK
2 Input signal check.
PREPARATION:
See input signal check on page DI−410.
CHECK:
Check the indicator light when shifting into except D position.
OK:
The indicator light goes off when shifting into except
D position.
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI−419).
NG

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I00017
I00026
ON
N&C
(−)
(+)
− DIAGNOSTICSCRUISE CONTROL SYSTEM
DI−445
1996 TOYOTA T100 (RM449U)
3 Check voltage between terminal N & C of cruise control ECU connector and
body ground.
PREPARATION:
Turn ignition switch ON.
CHECK:
Measure each voltage between terminal N & C of ECU connec-
tor and body ground when shifting into D position and other
positions.
OK:
Shift PositionVoltage
D position10 − 16 V
Other positionsBelow 1 V
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI−419).
NG
4 Check harness and connector between cruise control ECU and park/neutral
position switch (See page IN−16).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU (See
page IN−26).

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DI−446
− DIAGNOSTICSCRUISE CONTROL SYSTEM
1996 TOYOTA T100 (RM449U)
Clutch Switch Circuit
CIRCUIT DESCRIPTION
When the clutch pedal is depressed, the clutch switch sends a signal to the cruise control ECU. When the
signal is input to the cruise control ECU during cruise control driving, the cruise control ECU cancels cruise
control.
WIRING DIAGRAM
DI359−02