1996 TOYOTA LAND CRUISER Workshop Manual

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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DI5OB−02
Duty Ratio =A + BA
x 100 (%)
ON
OFF A
B
1 cycle
I00488
Cruise Control ECU
MC
11
C17 MO
L
Cruise Control Actuator
L−RC17
7
6 12
C4
C4
DI−296
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
1996 LAND CRUISER (RM451U)
CIRCUIT INSPECTION
DTC 11 Actuator Motor Circuit
CIRCUIT DESCRIPTION
The actuator motor is operated by signals from the ECU. Acceleration and deceleration signals are trans-
mitted by changes in the Duty Ratio (See note below).
Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle. For e\
xample, if A is the period of continuity
in one cycle, and B is the period of non −continuity, then.
DTC No.Detection ItemTrouble Area
11Short in actuator motor circuit.
Actuator motor
 Harness or connector between cruise control ECU and
actuator motor
 Cruise control ECU
WIRING DIAGRAM
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I00248
76
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
DI−297
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
1 Check resistance between terminals MO and MC of actuator motor.
PREPARATION:
(a) Turn ignition switch OFF.
(b) Disconnect the actuator connector.
CHECK:
Measure resistance between terminals 6 and 7.
HINT:
If control plate position is fully opened or fully closed, resistance
can not measure.
OK:
Resistance: more than 4.2 Ω
NG Replace cruise control actuator.
OK
2 Check for open and short in harness and connectors between cruise contro\
l ECU and actuator motor (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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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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I00247
4
5
DI−300
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
1996 LAND CRUISER (RM451U)
3 Check resistance between terminals L and GND of actuator magnetic clutch.
PREPARATION:
(a) Turn ignition switch OFF.
(b) Disconnect the actuator connector.
CHECK:
Measure resistance between terminals 4 and 5.
OK:
Resistance: 34.65 − 42.35 Ω.
NG Replace cruise control actuator.
OK
4 Check for open and short in harness and connectors between cruise contro\
l ECU and actuator magnetic clutch, actuator magnetic clutch and body grou\
nd
(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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I00490
Cruise Control ECUVR1 VR2
VR3
23
24
25
Y
Y−G Y−L
1
2 3
C4
Cruise Control Actuator
C17
C17 C17
C4
C4
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
DI−301
1996 LAND CRUISER (RM451U)
DTC 13 Actuator Position Sensor Circuit
CIRCUIT DESCRIPTION
The circuit detects the rotation position of the actuator control plate and\
sends a signal to the ECU.
DTC No.Detection ItemTrouble Area
13Position sensor detects abnormal voltage.
Actuator position sensor
 Harness or connector between cruise control ECU and
actuator position sensor
 Cruise control ECU
WIRING DIAGRAM
DI5OD−02
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AB0119
I00135I00130
I00161VR2
VR3
ON
Fully Close Side
Fully Open Side
Control Plate
(−)
(+)
I00006
1
3
DI−302
−
DIAGNOSTICS CRUISE CONTROL SYSTEM
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
1 Check resistance between terminals VR2 and VR3 of cruise control ECU connec-
tor.
PREPARATION:
(a) Remove the ECU with connectors still connected.
(b) Turn ignition switch OFF.
CHECK:
Measure voltage between terminals VR2 and VR3 of ECU con-
nector while turning control plate slowly by hand from the decel-
eration side to the acceleration side.
OK:
Voltage:
Fully closed: Approx. 1.3 V
Fully opened: Approx. 4.1 V
In addition, as the control plate is turned, the voltage
should increase gradually without interruption.
NG Proceed to next circuit inspection shown on problem symptoms table (See page DI−295 ).
OK
2 Check resistance between terminals VR1 and VR3 of actuator position sens\
or.
PREPARATION:
(a) Turn ignition switch OFF.
(b) Disconnect the actuator connector.
CHECK:
Measure resistance between actuator terminal 1 and 3 of ac-
tuator connector.
OK:
Resistance: 1.8 − 2.2 kΩ (25 °C)
NG Replace cruise control actuator.
OK
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