low oil pressure TOYOTA LAND CRUISER 1986 Factory Repair Manual

I01390
Condition: Insufficient cooling
I01392
Condition: Insufficient cooling
NOTE : These gauge indica-
tions are shown when the
refrigeration system has
been opened and the refrig-
erant charged without vacu-
um purging.
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-7
2732 Author
: Date
:
2004 LAND CRUISER (RM1071U)
(6) Refrigerant overcharged or insufficient cooling of
condenser.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy

Pressure too high on both low
and high pressure sides

No air bubbles seen through the
sight glass even when the engine
rpm is lowered
Unable to develop sufficient per-
formance due to excessive refrig-
eration system

Insufficient cooling of condenser
Excessive refrigerant in
cycle " refrigerant over charged

Condenser cooling " condenser
fins clogged or cooling fan faulty
(1) Clean condenser
(2) Check cooling fan with fluid
coupling operation
(3) If (1) and (2) are in normal
state, check amount of refrigerant,
and charge proper amount of re-
frigerant
(7) Air present in refrigeration system.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy

Pressure too high on both low
and high pressure sides

The low pressure piping hot to
touch

Bubbles seen in sight glass
Air entered in refrigeration system

Air present in refrigeration sys-
tem

Insufficient vacuum purging
(1) Check compressor oil to see if
it is dirty or insufficient
(2) Evacuate air and charge new
refrigerant

AC2810
AC1HK-04
AC2811
N11084
Wrong Okay
HI LO HILO
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-1
2726 Author
: Date
:
2004 LAND CRUISER (RM1071U)
AIR CONDITIONING SYSTEM
PRECAUTION
1. DO NOT HANDLE REFRIGERANT IN AN ENCLOSED
AREA OR NEAR AN OPEN FLAME
2. ALWAYS WEAR SAFETY GLASSES FOR EYE
PROTECTION
3. AVOID YOUR EYES AND SKIN TO CONTACT WITH
LIQUID REFRIGERANT
If you get the liquid refrigerant in your eyes or on your skin:
(a) Wash out the area with lots of cold water.
CAUTION:
Do not rub your eyes or skin.
(b) Apply clean petroleum jelly to the skin.
(c) Go immediately to a physician or hospital for professional
treatment.
4. NEVER HEAT CONTAINER OR EXPOSE IT TO NAKED
FLAME
5. DO NOT DROP CONTAINER NOR APPLY PHYSICAL
SHOCKS TO IT.
6. DO NOT OPERATE COMPRESSOR WITHOUT
ENOUGH REFRIGERANT IN REFRIGERANT SYSTEM
If there is not enough refrigerant in the refrigerant system, oil lu-
brication will be insufficient and compressor burnout may occur.
To avoid this, always keep enough refrigerant in the refrigerant
system.
7. DO NOT OPEN HIGH PRESSURE MANIFOLD VALVE
WHILE COMPRESSOR IS OPERATING
If the high pressure valves opened, refrigerant flows in the re-
verse direction and could cause the charging cylinder to rup-
ture, so open and close the only low pressure valve.
8. DO NOT OVERCHARGE REFRIGERANT SYSTEM
WITH REFRIGERANT
If refrigerant is overcharged, it causes problems such as insuffi-
cient cooling, poor fuel economy, engine overheating etc.

I06184
F
1/2
E 321
- BODY ELECTRICALCOMBINATION METER
BE-67
2440 Author
: Date
:
6. INSPECT FUEL SENDER GAUGE VOLTAGE
(a) Apply voltage (4.5 V - 5.0 V) between terminals 2 and 3.
(b) Measure voltage between terminals 1 and 2 for each float
position.
Float position mm (in.)Voltage (V)
F: Approx. 85.3 (3.36)Approx. 4.60 ± 0.1
1/2: Approx. 1.7 (0.67)Approx. 2.45 ± 0.1
E: Approx. 91.9 (3.62)Approx. 0.30 ± 0.1
If voltage value is not as specified, replace main sender gauge.
7. INSPECT LOW OIL PRESSURE WARNING LIGHT
(a) Disconnect the connector from the low oil pressure
switch.
(b) Turn the ignition switch ON.
(c) Connect the terminal of wire harness side connector and
ground, then check the warning light.
8. INSPECT PARKING BRAKE WARNING LIGHT
(a) Disconnect the connector from the parking brake switch
and ground terminal on the wire harness side connector.
(b) Turn the ignition switch ON and check that the warning
light lights up.
9. INSPECT BRAKE WARNING LIGHT
(a) Disconnect the connector from the brake fluid level warn-
ing switch and ground terminal on the wire harness side
connector.
(b) Turn the ignition switch ON and check that the warning
light lights up.
10. INSPECT BRAKE FLUID LEVEL WARNING SWITCH
(a) Remove the reservoir tank cap and retainer.
(b) Disconnect the connector.
(c) Check that the continuity exists between the terminal.
(d) Use syphon, etc., to take fluid out of the reservoir tank.
(e) Check that the continuity exists between terminals.
(f) Pour the fluid back in the reservoir tank.
11. INSPECT OPEN DOOR WARNING LIGHT
(a) DIsconnect the connector from the driver door courtesy
switch and ground terminal on the wire harness side con-
nector.
(b) Turn the ignition switch ON and check that the warning
light lights up.

BO1JQ-03
H05391
150 mm (5.91 in.)
- BODYBACK DOOR STAY
BO-31
2605 Author
: Date
:
2004 LAND CRUISER (RM1071U)
BACK DOOR STAY
REPLACEMENT
1. REMOVE BACK DOOR STAY
(a) Remove the bolts and back door stay from the back door.
HINT:
While supporting the back door with your hand, remove the
back door stay.
(b) Remove the bolt and back door stay from the body.
2. IF NECESSARY, REPLACE BACK DOOR STAY
NOTICE:
When handling the back door stay.

Do not disassemble the back door stay because the
cylinder is filled with pressurized gas.

If the back door stay is to be replaced, drill a 2.0 - 3.0
mm (0.079 - 0.118 in.) hole in the bottom of the back
door stay as shown in the illustration to completely
release the high-pressure gas before disposing of it.

When drilling, chips may fly out so work carefully.

The gas is colorless, odorless and non-toxic.

When working, handle the back door stay carefully.
Never score or scratch the exposed part of the piston
rod, and never allow paint or oil to get on it.

Do not turn the piston rod and cylinder with the back
door stay fully extended.
3. INSTALL BACK DOOR STAY
(a) Install the bolt and back door stay to the body.
Torque: 17.5 N´m (178 kgf´cm, 13 ft´lbf)
(b) Install the bolts and back door stay to the back door.
Torque: 13 N´m (133 kgf´cm, 10 ft´lbf)

BO1J9-03
H04840
150 mm (5.91 in.)
- BODYHOOD SUPPORT
BO-7
2581 Author
: Date
:
2004 LAND CRUISER (RM1071U)
HOOD SUPPORT
REPLACEMENT
1. REMOVE HOOD SUPPORT
(a) Remove the bolt and hood support from the hood.
HINT:
While supporting the hood by hand, remove the hood support
from the hood.
(b) Remove the bolt and hood support.
2. IF NECESSARY, REPLACE HOOD SUPPORT
NOTICE:
Handling the hood support

Do not disassemble the support as the cylinder is
filled with pressurized gas.

If the hood support is to be replaced, drill a 2.0 - 3.0
mm (0.079 - 0.118 in.) hole in the area shown in the il-
lustration to completely release the high pressure
gas before disposing of it.

When drilling, chips may fly out so work carefully.

The gas is colorless, odorless and non - toxic.

When working, handle the hood support carefully.
Never score or scratch the exposed part of the piston
rod, and allow any paint or oil to get on it.

Do not turn the piston rod and cylinder with the hood
support fully extended.
3. INSTALL HOOD SUPPORT
(a) Install the bolt and hood support to the body.
(b) Install the bolt and hood support to the hood.

F04472
SST
SST
BR12D-05
F04473
SST
F13233
30 mm
Deeper
Socket BR-62
- BRAKEHYDRAULIC BRAKE BOOSTER
2198 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DISASSEMBLY
1. PLACE HYDRAULIC BRAKE BOOSTER IN VISE
Using SST, set the hydraulic brake booster in vise.
SST 09630-00014 (09631-00142),
09950-60010 (09951-00180, 09951-00190)
2. REMOVE FLUID LEVEL WARNING SWITCH CONNEC-
TOR CLAMP
(a) Disconnect the connector.
(b) Remove the bolt and clamp.
3. REMOVE RESERVOIR AND GROMMETS
(a) Remove reservoir cap.
(b) Remove the 3 set screws and pull out the reservoir.
Torque: 1.7 N´m (17.5 kgf´cm, 15.2 in.´lbf)
(c) Remove the 3 grommets.
4. REMOVE CLEVIS AND CYLINDER BOOT
(a) Loosen the lock nut, then remove the clevis and lock nut.
Torque: 25 N´m (260 kgf´cm, 19 ft´lbf)
(b) Remove the cylinder boot.
5. REMOVE BRAKE ACTUATOR TUBE NO. 1
Using SST, remove the brake actuator tube No. 1.
SST 09023-00100
Torque: 15 N´m (155 kgf´cm, 11 ft´lbf)
6. REMOVE BOOSTER PUMP AND ASSEMBLY
(a) Remove the actuator hose.
(b) Remove the 4 screws and wire harness from the booster
and pump.
(c) Remove the 2 bolts, accumulator bracket.
(d) Remove the 2 bolts and booster pump motor assembly.
(e) Remove the bolt and No. 1 pump bracket.
(f) Remove the 2 washers, 2 cushions, 2 collars and sleeve.
(g) Remove the 2 bolts and No. 2 pump bracket.
(h) Remove the cushion from No. 2 pump bracket.
7. ABS & BA & TRAC & VSC only:
REMOVE MASTER CYLINDER PRESSURE SENSOR
Using 30 mm deeper socket wrench and remove the oil pres-
sure sensor.
Torque: 81 N´m (830 kgf´cm, 60 ft´lbf)
NOTICE:
If replacing the master cylinder pressuer sensor, since the
sensor is non-reusable, use a sensor of the supply part No
shown below.
PART NO: 89637-30050

CO0IO-06
- COOLINGCOOLANT
CO-1
1762 Author
: Date
:
2004 LAND CRUISER (RM1071U)
COOLANT
INSPECTION
HINT:
Check the coolant level when the engine is cold.
1. CHECK ENGINE COOLANT LEVEL AT RADIATOR RESERVOIR
The engine coolant level should be between the ºLOWº and ºFULLº lines at normal temperature
(20°C(68°F)).
If low, check for leaks and add ºToyota Super Long Life Coolantº or similar high quality ethylene glycol based
non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid organic acid technology
up to the ºFULLº line.
2. CHECK ENGINE COOLANT QUALITY
(a) Remove the radiator cap.
CAUTION:
To avoid the danger of being burned, do not remove the radiator cap while the engine and radiator
are still hot, as fluid and steam can be blown out under pressure.
(b) There should not be any excessive deposits of rust or scale around the radiator cap or radiator filler
hole, and the coolant should be free from oil.
If excessively dirty, clean the coolant passages and replace the coolant.
(c) Reinstall the radiator cap.

DI-586- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
779 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC C1253 / 53 Motor Relay Circuit
CIRCUIT DESCRIPTION
The ABS motor 1 relay and ABS motor 2 relay supply power to the hydraulic brake booster pump motor.
While the ABS & BA & TRAC & VSC are activated, the ECU switches the motor relay ON and operates the
hydraulic brake booster pump motor.
DTC No.DTC Detecting ConditionTrouble Area
C1253 / 53
When any of the following 1. through 4. is detected:
1. After turning the ignition switch ON, open in the relay
coil is detected for more than 1 sec.
2. When the pressure switch does not control motor
driving, the condition that the motor relay is always ON
continues for more than 1 sec. due to short circuit.
3. When the pressure switch (PH) detects the low
pressure or while the pump motor operates to increase
the pressure, the condition that the motor relay does not
turn ON continues for more than 0.2 sec.
4. When pressure switch does not control motor driving,
the condition that the motor relay is always ON due to
the welded contact continues for more than 2 sec.

ABS motor 1 or ABS motor 2 relay

ABS motor 1 or ABS motor 2 relay circuit

Hydraulic brake booster pump motor circuit
DIC9V-02

D01769
- DIAGNOSTICSAUTOMATIC TRANSMISSION
DI-487
680 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P2757Torque Converter Clutch Pressure Control Solenoid
Performance(Shift Solenoid Valve SLU)
SYSTEM DESCRIPTION
The ECM uses the signals from the Throttle Position Sensor
and Air-flow Meter to monitor the engagement condition of the
lock-up clutch.
Then the ECM compares the engagement condition of the
lock-up clutch with the lock-up schedule in the ECM memory
to detect mechanical trouble of the shift solenoid valve SLU,
valve body, torque converter clutch and automatic transmission
assembly (clutch, brake or gear etc.).
DTC No.DTC Detecting ConditionTrouble Area
P2757
Lock-up does not occur when driving in the lock-up range
(normal driving at 80 km/h [50 mph]), or lock-up remains ON
in the lock-up OFF range.
(2-trip detection logic)
Shift solenoid valve SLU is stuck open or closed

Valve body blocked up or stuck

Lock-up clutch

Automatic transmission assembly
MONITOR DESCRIPTION
The ECM controls the oil pressure to the lock-up clutch based on engine-load information from the throttle
position sensor, crankshaft position sensor, input speed sensor, and the oil pressure sensor for shift-sole-
noid SLU. The ECM commands the shift-solenoid SLU using a duty-cycle control signal. In turn, the shift
solenoid operates the lock-up control valve and causes lock-up or flexible lock-up of the torque converter
clutch.
To monitor the condition of the lock up clutch, the ECM monitors the signals from the input speed sensor,
crank position sensor, the throttle position sensor, and air flow meter. The ECM uses this information to deter-
mine when the vehicle's torque converter clutch should be locked-up. The ECM can detect many mechani-
cal problems in the shift solenoids, valve body, and the transmission clutches, brakes, and gears. If the ECM
detects that the torque converter clutch locked below the minimum lock-up speed, it will illuminate the MIL
and store the DTC.
MONITOR STRATEGY
RltdDTCP2757Shift solenoid valve SLU/OFF malfunctionRelated DTCsP2757Shift solenoid valve SLU/ON malfunction
MainShift solenoid valve SLU
Required sensors/ComponentsSubValve body, Vehicle speed sensor, Throttle position sensor, Speed sensor
(NT), Speed sensor (NO)
Frequency of operationContinuous
DtiOFF malfunction2 sec.DurationON malfunction1.8 sec.
MIL operation2 driving cycles
Sequence of operationNone
DIB3L-02

Current flow to solenoid
Lock-up
Operation
Pressure
BE4056D00160
1 cycle ON
OFFDuty Ratio
=
A + B
A
y 100 (%) (*)
- DIAGNOSTICSAUTOMATIC TRANSMISSION
DI-491
684 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P2759Torque Converter Clutch Pressure Control Solenoid
Control Circuit Electrical(Shift Solenoid Valve SLU)
CIRCUIT DESCRIPTION
The amount of current flow to the solenoid is controlled by the
(*) duty ratio of the ECM output signal. The higher the duty ratio
becomes, the higher the lock-up hydraulic pressure becomes
during the lock-up operation.
(*) Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle.
For example, if A is the period of continuity in one cycle, and B
is the period of non-continuity, then
DTC No.DTC detection conditionTrouble Area
P2759
The following condition is detected. (1-trip detection logic)
SLU output signal's duty ON of 3.3 msec. or more with duty
ratio of least 95% lasts for 1 second.
Open or short in shift solenoid valve SLU circuit

Shift solenoid valve SLU

ECM
MONITOR DESCRIPTION
The ECM controls the oil pressure to the lock-up clutch based on engine-load information from the throttle
position sensor, crankshaft position sensor, input speed sensor, and the oil pressure sensor for shift-sole-
noid SLU. The ECM commands the shift-solenoid SLU using a duty-cycle control signal. In turn, the shift
solenoid operates the lock-up control valve and cause lock-up or flexible lock-up of the torque converter
clutch. The ECM illuminates the MIL and store the DTC when ECM detects an open or a short circuit malfunc-
tion in the shift solenoid valve SLU.
MONITOR STRATEGY
Related DTCsP2759Shift solenoid valve SLU/Range check
Required sensors/ComponentsShift solenoid valve SLU
Frequency of operationContinuous
Duration1 sec.
MIL operationImmediate
Sequence of operationNone
DIB3M-02