1996 TOYOTA LAND CRUISER Cruise control

Input SignalIndicator Light
Blinking Pattern
Stop Light
switch ON
Light ON
OFF SW OFF
SW ON
DI−314
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
1996 LAND CRUISER (RM451U)
Stop Light Switch Circuit
CIRCUIT DESCRIPTION
When the brake pedal is depressed, the stop light switch sends a signal to th\
e 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 normally applies through the S\
TOP 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−298 for operation of the magnetic clutch).
WIRING DIAGRAM
See page DI−298 .
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−24 ).
OK
2 Input signal check.
CHECK:
(a) See input signal check on DI−286.
(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−295 ).
NG
DI5OI−02
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AB0119I00015 I00024
ON
STP−
(−) (+)
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
DI−315
1996 LAND CRUISER (RM451U)
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 − 14 V
ReleasedBelow 1 V
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI−295 ).
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 ).
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I00493
Cruise Control ECUIDL
C17 21
G−W
ECM
IDL IH1
E5 19
G−W
11
Threottle Position Sensor G−W
DI−316
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
1996 LAND CRUISER (RM451U)
Idle Switch Circuit
CIRCUIT DESCRIPTION
When the idle switch in 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 val\
ue 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
DI5OJ−02
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AB0119I00053 I00031
ON
IDL
(−) (+)
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
DI−317
1996 LAND CRUISER (RM451U)
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 − 14 V
Fully closedBelow 2 V
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI−295 ).
NG
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 throttle position sensor circuit (See page DI−35).
NG Replace throttle position sensor.
OK
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I00052
Throttle Position Sensor
3
4
DI−318
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
1996 LAND CRUISER (RM451U)
4 Check throttle position sensor.
PREPARATION:
Disconnect the throttle position sensor connector.
CHECK:
Measure resistance between terminals 3 and 4 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 2.3 kΩ
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−28 ).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU
(See page IN−28 ).
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I00494
Cruise Control ECUECT
22 9
15
9
E4S2
R−Y
ECM
E7
OD1
ODC17
18
G−R
G−O
C17
R−Y
R−Y
2 EC2 IH2
Ellectronically Con trolled
Transmission Solenoid
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
DI−319
1996 LAND CRUISER (RM451U)
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 si\
gnal
to prevent upshift until the end of the up hill slope is sent from the cru\
ise 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 uph\
ill slope, and the gear shifts
are reduced and gear shift points in the electronically controlled transmis\
sion are changed.
WIRING DIAGRAM
DI5OK−02
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AB0119I00012 I00025
ON
OD
(−) (+)
DI−320
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
1996 LAND CRUISER (RM451U)
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 controlledtransmission (See page DI−129 ).
OK
2 Check voltage between terminal OD of harness side connector of cruise co\
ntrol 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 harness side connec-
tor of ECU and body ground.
OK:
Voltage: 10 − 14 V
NG Go to step 5.
OK
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I00019
ECT
(−) (+)
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
DI−321
1996 LAND CRUISER (RM451U)
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
ON8 − 14 V
OFFBelow 0.5 V
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI−295 ).
NG
4 Check harness and connector between terminal ECT of cruise control ECU a\
nd electronically controlled transmission solenoid (See page IN−28).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU.
5 Check harness and connector between terminal OD of cruise control ECU an\
d 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 ).
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