DI5OA−02
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
DI−295
1996 LAND CRUISER (RM451U)
PROBLEM SYMPTOMS TABLE
SymptomSuspect AreaSee page
SET not occourring or CANCEL occurring.
(DTC is Normal)
1. Main Switch Circuit (Cruise control switch)
2. Vehicle Speed Sensor
3. Control Switch Circuit (Cruise control switch)
4. Stop Light Switch Circuit
5. Park/Neutral Position Switch Circuit
6. Actuator Motor Circuit
7. Cruise Control Cable
8. Cruise Control ECUDI−330
DI−306
DI−311
DI−314
DI−322
DI−296
DI−336 IN−28
SET not occurring or CANCEL occurring.
(DTC does not output)1. ECU Power Source Circuit
2. Cruise Control ECUDI−325IN−28
Actual vehicle speed deviates above or below the set speed.
1. Cruise Control Cable
2. Vehicle Speed Signal Abnormal
3. Electronically Controlled Transmission Communication
Circuit
4. Actuator Motor Circuit
5. Idle Signal Circuit (main throttle position sensor)
6. Cruise Control ECUDI−336
DI−310
DI−319
DI−296
DI−316IN−28
Gear shifting frequent between 3rd O/D when driving on uphill
road. (Hurting)1. Electronically Controlled Transmission Communication
Circuit
2. Cruise Control ECUDI−319
IN−28
Cruise control not cancelled, even when brake pedal is de-
pressed.
1. Cruise Control Cable
2. Stop Light Switch Circuit
3. Actuator Motor Circuit
4. Cruise Control ECUDI−336
DI−314
DI−296IN−28
Cruise control not cancelled, even when transmission is shifted to
”N” postion.
1. Cruise Control Cable
2. Park/Neutral Position Switch Circuit
3. Actuator Motor Circuit
4. Cruise Control ECUDI−336
DI−322
DI−296IN−28
Control switch does not operate.
(SET/COAST, A CC/RES, CANCEL not possible)
1. Cruise Control Cable
2. Control Switch Circuit
3. Actuator Motor Circuit
4. Cruise Control ECUDI−336
DI−311
DI−296 IN−28
SET possible at 40 km/h (25 mph) or less, or CANCEL does not
operate at 40 km/h (25 mph) or less.
1. Cruise Control Cable
2. Vehicle Speed Signal Abnormal
3. Actuator Motor Circuit
4. Cruise Control ECUDI−336
DI−310
DI−296IN−28
Poor response is ACCEL and RESUME modes.
1. Cruise Control Cable
2. Electronically Controlled Transmission Communication
Circuit
3. Actuator Motor Circuit
4. Cruise Control ECUDI−336
DI−319
DI−296IN−28
O/D does not RESUME, even though the road is not uphill.
1. Electronically Controlled Transmission Communication
Circuit
2. Cruise Control ECUDI−319
IN−28
DTC memory is erased.1. Back− up Power Source Circuit
2. Cruise Control ECUDI−328 IN−28
DTC is not output, or is output when is should not be.1. Diagnosis Circuit
2. Cruise Control ECUDI−319IN−28
Cruise MAIN indicator light remains ON or fall to light up.1. Cruise MAIN Indicator Light Switch CircuitDI−332
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I00489
Cruise Control ECUL
L−
W−B
1
5
4 3
2 R
1026
C4 Stop Light Switch
4
R−G
Cruise
Control Actuator
C17
C17
C17
C4S13
S13 S13
S13
G−O G−WF11F11
1
2
STOP
Instrument Panel Fuse Block
W
EA3
W
3
1
F8
Battery Fusible Link
FL MAIN
STP−
DI−298
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
1996 LAND CRUISER (RM451U)
DTC 12 Actuator Magnetic Clutch Circuit
CIRCUIT DESCRIPTION
This circuit turns on the magnetic clutch inside the actuator during cruise \
control operation according to the
signal from the ECU. If a malfunction occurs in the actuator or speed sensor, etc. during cruise control opera-
tion, the rotor shaft between the motor and control plate is released.
When the brake pedal is depressed, the stop light switch turns on, supplying electrical power to the stop light.
Power supply to the magnetic clutch is mechanically cut and the magnetic clut\
ch is turned OFF.
When driving downhill, if the vehicle speed exceeds the set speed by 15 km/h\
(9 mph), the ECU turns the
safety magnet clutch OFF. If the vehicle speed later drops to within 10 km/h (6 mph) above the\
set speed,
then cruise control at the set speed is resumed.
DTC No.Detection ItemTrouble Area
12 Short in actuator magnetic clutch circuit.
Open (0.8 sec.) in actuator magnetic clutch circuit.
STOP Fuse
Stop light switch
Actuator magnetic clutch
Harness or connector between cruise control ECU and
actuator magnetic clutch, actuator magnetic clutch and body
ground
Cruise control ECU
WIRING DIAGRAM
DI5OC−02
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N18670
Instrument Panel Fuse Block
STOP Fuse
I00133
1
2
43
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
DI−299
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
1 Check STOP fuse.
PREPARATION:
(a) Turn ignition switch OFF.
(b) Remove the STOP fuse from instrument panel fuse block.
CHECK:
Check fuse continuity.
OK:
There is continuity.
NG Replace STOP fuse.
OK
2 Check stop light switch.
PREPARATION:
Disconnect the stop light switch connector.
CHECK:
Check continuity between terminals.
Switch positionContinuity
Switch pin free
(Brake pedal depressed)1 − 2
Switch pin pushed in
(Brake pedal released)3 − 4
NG Replace stop light switch.
OK
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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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EM−2
−
ENGINE MECHANICAL CO/HC
505
Author: Date:
1996 LAND CRUISER (RM451U)
6. TROUBLESHOOTING
If the CO/HC concentration does not comply with regulations,
troubleshoot in the order given below.
See the table below for possible causes, and then inspect and
correct the applicable causes if necessary.
COHCProblemsCauses
NormalHighRough idle
3. Faulty ignitions:
Incorrect timing
Fouled, shorted or improperly gapped plugs
Open or crossed high −tension cords
Cracked distributor cap
4. Incorrect valve clearance
5. Leaky EGR valve
6. Leaky intake and exhaust valves
7. Leaky cylinders
LowHighRough idle
(Fluctuating HC reading)
1. Vacuum leaks:
PCV hose
EGR valve
Intake manifold
Air intake chamber
Throttle body
IAC valve
Brake booster line
2. Lean mixture causing misfire
HighHighRough idle
(Black smoke from exhaust)
1. Restricted air filter
2. Faulty SFI systems:
Faulty pressure regulator
Clogged fuel return line
Defective ECT sensor
Faulty ECM
Faulty injector
Faulty throttle position sensor
Faulty MAF meter
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MA02R−04
MA−4
−
MAINTENANCE UNDER HOOD
44
Author: Date:
1996 LAND CRUISER (RM451U)
UNDER HOOD
GENERAL MAINTENANCE
1. GENERAL NOTICE
Maintenance items may vary from country to country. Check the owner’s manual supplement in which
the maintenance schedule is shown.
Every service item in the periodic maintenance schedule must be performe\
d.
Periodic maintenance service must be performed according to whichever interval in\
the periodic main-
tenance schedule occurs first, the odometer reading (miles) or the time inter\
val (months).
Maintenance service after the last period should be performed at the same interval \
as before unless
otherwise noted.
Failure to do even one item can cause the engine to run poorly and incre\
ase exhaust emissions.
2. WINDSHIELD WASHER FLUID
Check that there is sufficient fluid in the tank.
3. ENGINE COOLANT LEVEL Check that the coolant level is between the FULL and LOW lines on the se\
e −through reservoir.
4. RADIATOR AND HOSES
(a) Check that the front of the radiator is clean and not blocked with leave\
s, dirt or bugs.
(b) Check the hoses for cracks, kinks, rot or loose connections.
5. BATTERY ELECTROLYTE LEVEL
Check that the electrolyte level of all battery cells is between the upp\
er and lower level lines on the case.
If level is low, add distilled water only.
6. BRAKE FLUID LEVELS
Check that the brake fluid level is near the upper level line on the see\
−through reservoir.
7. ENGINE DRIVE BELTS
Check drive belt for fraying, cracks, wear or oiliness.
8. ENGINE OIL LEVEL
Check the level on the dipstick with the engine turned off.
9. POWER STEERING FLUID LEVEL
(a) Check the level on the dipstick.
(b) The level should be in the HOT or COLD range depending on the fluid temp\
erature.
10. AUTOMATIC TRANSMISSION FLUID LEVEL
(a) Park the vehicle on a level surface.
(b) With the engine idling and the parking and foot brake applied, shift the sel\
ector into all positions from the P to L, and then shift into the P.
(c) Pull out the dipstick and wipe off the fluid with a clean rag. Re −insert the dipstick fully and check that
the fluid level is in the HOT range.
(d) Do this check with the fluid at normal driving temperature (70 − 80°C (158 − 176° F)).
HINT:
Wait about 30 minutes before checking the fluid level after extended driving\
at high speeds in hot weather,
driving in heavy traffic or with a trailer.
11. EXHAUST SYSTEM
Visually inspect for cracks, holes or loose supports.
If any change in the sound of the exhaust or smell of the exhaust fumes is\
noticed, have the cause located
and corrected.
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MA0055
MA02T−03
MA−6
−
MAINTENANCE BRAKE
46
Author: Date:
1996 LAND CRUISER (RM451U)
BRAKE
INSPECTION
1. INSPECT BRAKE LINE PIPES AND HOSES
HINT:
Check in a well lighted area. Check the entire circumference
and length of the brake hoses using a mirror as required. Turn
the front wheels fully right or left before checking the front brake.
(a) Check all brake lines and hoses.
Check for damage.
Check for wear.
Check for deformation.
Check for cracks.
Check for corrosion.
Check for leaks.
Check for bends.
Check for twists.
(b) Check all clamps for tightness and connections for leak- age.
(c) Check that the hoses and lines are clear of sharp edges, moving parts and the exhaust system.
(d) Check that the lines installed in grommets pass through the center of the grommets.
2. INSPECT FRONT BRAKE P ADS AND DISCS (See page
BR−27 )
3. INSPECT REAR BRAKE PADS AND DISCS (See page
BR−36 )
4. INSPECT PARKING BRAKE LININGS AND DRUMS
(See page BR−42 )
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