5A–5 BRAKE CONTROL SYSTEM
FR
Front Right
GEN
Generator
MV
Millivolts
RL
Rear Left
RR
Rear RightRPS
Revolution per Second
VDC
Vo l t s D C
VA C
Vo l t s A C
W/L
Warning Light
WSS
Wheel Speed Sensor
General Diagnosis
General Information
ABS malfunction can be classified into two types, those
which can be detected by the ABS warning light and those
which can be detected as a vehicle abnormality by the
driver.
In either case, locate the fault in accordance with the
“BASIC DIAGNOSTIC FLOWCHART” and repair.
Please refer to Section 5C for the diagnosis of
mechanical troubles such as brake noise, brake judder
(brake pedal or vehicle vibration felt when braking),
uneven braking, and parking brake trouble.
ABS Service Precautions
Required Tools and Items:
Box Wrench
Brake Fluid
Special Tool
Some diagnosis procedures in this section require the
installation of a special tool.
J-39200 High Impedance Multimeter
When circuit measurements are requested, use a circuit
tester with high impedance.
Computer System Service Precautions
The Anti-lock Brake System interfaces directly with the
Electronic Hydraulic Control Unit (EHCU) which is a
control computer that is similar in some regards to the
Powertrain Control Module. These modules are designed
to withstand normal current draws associated with
vehicle operation. However, care must be taken to avoid
overloading any of the EHCU circuits. In testing for opens
or shorts, do not ground or apply voltage to any of the
circuits unless instructed to do so by the appropriate
diagnostic procedure. These circuits should only be
tested with a high impedance multimeter (J-39200) or
special tools as described in this section. Power should
never be removed or applied to any control module with
the ignition in the “ON” position.
Before removing or connecting battery cables, fuses or
connectors, always turn the ignition switch to the “OFF”
position.
General Service Precautions
The following are general precautions which should be
observed when servicing and diagnosing the Anti-lock
Brake System and/or other vehicle systems. Failure toobserve these precautions may result in Anti-lock Brake
System damage.
If welding work is to be performed on the vehicle using
an electric arc welder, the EHCU and valve block
connectors should be disconnected before the
welding operation begins.
The EHCU and valve block connectors should never
be connected or disconnected with the ignition “ON” .
EHCU of the Anti-lock Brake System are not
separately serviceable and must be replaced as
assemblies. Do not disassemble any component
which is designated as non-serviceable in this
Section.
If only rear wheels are rotated using jacks or drum
tester, the system will diagnose a speed sensor
malfunction and the “ABS” warning light will
illuminate. But actually no trouble exists. After
inspection stop the engine once and re-start it, then
make sure that the “ABS” warning light does not
illuminate.
If the battery has been discharged
The engine may stall if the battery has been completely
discharged and the engine is started via jumper cables.
This is because the Anti-lock Brake System (ABS)
requires a large quantity of electricity. In this case, wait
until the battery is recharged, or set the ABS to a
non-operative state by removing the fuse for the ABS
(40A). After the battery has been recharged, stop the
engine and install the ABS fuse. Start the engine again,
and confirm that the ABS warning light does not light.
Note on Intermittents
As with virtually any electronic system, it is difficult to
identify an intermittent failure. In such a case duplicating
the system malfunction during a test drive or a good
description of vehicle behavior from the customer may be
helpful in locating a “most likely” failed component or
circuit. The symptom diagnosis chart may also be useful
in isolating the failure. Most intermittent problems are
caused by faulty electrical connections or wiring. When
an intermittent failure is encountered, check suspect
circuits for:
Suspected harness damage.
Poor mating of connector halves or terminals not fully
seated in the connector body (backed out).
Improperly formed or damaged terminals.
5A–20
BRAKE CONTROL SYSTEM
Part Location (LHD model)
D08RW808
Legend
(1) F–2
(2) F–3
(3) H–33
(4) H–7, H–8, H–25
(5) H–46
(6) C–16
(7) C–63
(8) Fuse Box
(9) B–13 or B–14
(10) C–13
(11) H–5
(12) H–10, H–11(13) E–30
(14) C–41
(15) H–42
(16) C–85
(17) C–4 (EHCU)
(18) Relay & Fuse Box
(19) C–39
(20) H–12, H–13, H–15, H–16
(21) E–47, E–48, M–1
(22) E–42, E–43, M–8
(23) B–25
(24) I–10
(25) I–9
5A–34
BRAKE CONTROL SYSTEM
Part Location (RHD model)
D08RW623
Legend
(1) F–2
(2) F–3
(3) H–33
(4) H–7
(5) H–46
(6) C–16
(7) E–42, E–43, M–8
(8) E–47, E–48, M–1
(9) B–13 or B–14
(10) C–13
(11) H–4, H–5, H–6
(12) H–10, H–11
(13) E–4 (4JX1)(14) E–30 (4GJ2, 6VD1/6VE1)
(15) Fuse Box
(16) H–42
(17) C–41
(18) C–85
(19) C–4 (EHCU)
(20) Relay & Fuse Box
(21) C–39
(22) H–13, H–15, H–16, H–26, H–27
(23) I–10
(24) I–9
(25) H–12
(26) C–63
(27) B–25
5A–37 BRAKE CONTROL SYSTEM
StepNo Ye s
Action
5Is front 4WD controller normal?
Replace EHCU.
Go to Step 9
Replace 4WD
controller or
repair harness.
Go to Step 9
6Is transmission input normal? (Chart C-2 or TC-2)
Go to Step 7
Replace SW or
repair harness
Go to Step 9
7Is front 4WD controller normal?
Go to Step 8
Replace 4WD
controller or
repair harness.
Go to Step 9
8Is hydraulic unit grounded properly?Replace EHCU.
Go to Step 9Correct.
Go to Step 9
9Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 9
Chart A-4 Brake Pedal Feed Is Abnormal
StepActionYe sNo
1Is the stop light actuated when the brake pedal is depressed?Go to Step 2Go to Step 3
21. Turn the ignition switch off.
2. Disconnected EHCU connector.
3. Measure voltage between the EHCU connector terminal 10
and 15 when brake pedal is depressed.
Is the voltage equal to the battery voltage?
Go to Step 4
Harness NG
between brake
SW and EHCU.
Go to Step 7
3Is stop light fuse C-14 normal?
Go to Step 5
Replace fuse
C-14.
Go to Step 7
4Is there continuity between EHCU connector terminals, 12 and 15
to body ground?
Go to Step 6
Repair body
grounded
harness.
Go to Step 7
5Is the brake SW normal?Repair stop light
harness.
Go to Step 7Replace brake
SW.
Go to Step 7
6Is the check harness/connector for suspended disconnection?Hydraulic system
leakage or air
entry (Refer to
servicing
“Leakage or
brake fluid” )
Go to Step 7
Repair harness.
Go to Step 7
7Reconnect all components and ensure all components are
properly mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 7
5A–43 BRAKE CONTROL SYSTEM
Chart B-1 With the key in the ON position (Before starting the engine). Warning light (W/L)
is not activated.
StepActionYe sNo
1Is W/L fuse C-10 disconnected?Replace fuse.
Go to Step 5
Go to Step 2
2Is W/L burnt out?Replace W/L
bulb.
Go to Step 5
Go to Step 3
31. Turn the key off.
2. Disconnect EHCU connector.
3. Turn the key ON.
4. Measure the voltage between EHCU connector terminal 13
and 14.
Is the voltage equal to the battery voltage?
Go to Step 4
Repair harness
and connector.
Go to Step 5
4Is there continuity between EHCU connector terminals, 12 and 15
and body ground.Check harness
for suspected
disconnection.
No fault found:
Replace EHCU.
Go to Step 5
Repair harness
and connector.
Go to Step 5
5Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 5
Chart B-2 EHCU Abnormality (DTC 14)
StepActionYe sNo
11. Turn the key off.
2. Disconnect the EHCU connector.
3. Inspect EHCU ground.
Is there resistance between the EHCU connector terminals, 12
and 15 and body ground?
Go to Step 2
Repair the body
ground harness.
Go to Step 3
21. Turn the key off, connect the EHCU.
2. Erase the trouble code.
3. Turn Ignition off, then on, to perform system self-check.
4. If warning light remains on, display trouble codes once again.
Is the check trouble code 14?
Replace EHCU.
Go to Step 3
Inspect in
accordance with
the DTC
displayed.
31. Reconnect all components and ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 3
5A–47 BRAKE CONTROL SYSTEM
Chart B-7 Transfer Monitor (DTC 24)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
Is the EHCU connector terminal 9 line normally?
Go to Step 2
Repair
Go to Step 3
2Is the TOD ECU or 4WD controller normal?
Replace EHCU.
Go to Step 3
Repair or replace
TOD ECU or
4WD contrder.
Go to Step 3
31. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 3
Chart B-8 EHCU Pump Motor And Motor Relay Circuit (DTC 32)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure voltage between EHCU connector terminal 13 and
body ground.
Is the voltage equal to battery voltage?
Go to Step 2
Repair
fuse/harness
between battery
and EHCU
connector
terminal 13.
Go to Step 3
2Is there continuity between EHCU connector terminal 12 and
ground?
Go to Step 3
Repair between
EHCU connector
terminal 12 and
ground.
Go to Step 3
31. Reconnect all components and ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 3
Chart B-9 EHCU Pump Valve And Valve Relay Circuit (DTC 35)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure voltage between EHCU connector terminal 14 and
body ground.
Is the voltage equal to battery voltage?
Replace EHCU.
Go to Step 2
Repair fuse and
harness EHCU
connector
terminal 14 and
battery.
Go to Step 2
21. Reconnect all components and ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 2
6A–5
ENGINE MECHANICAL
4. Engine Lacks Compression
Condition
Possible causeCorrection
Engine lacks compressionSpark plug loosely fitted or spark
plug gasket defectiveTighten to specified torque or replace
gasket
Valve timing incorrectAdjust
Cylinder head gasket defectiveReplace gasket
Valve incorrectly seatedLap valve
Valve stem seizedReplace valve and valve guide
Valve spring weakened or brokenReplace
Cylinder or piston rings wornOverhaul engine
Piston ring seizedOverhaul engine.
Engine Compression Test Procedure
1. Start and run the engine until the engine reaches
normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and fuse
box.
6. Engage the starter and check that the cranking speed
is approximately 300 rpm.7. Install cylinder compression gauge into spark plug
hole.
8. With the throttle valve opened fully, keep the starter
engaged until the compression gage needle reaches
the maximum level. Note the reading.
9. Repeat the test with each cylinder.
If the compression pressure obtained falls below the
limit, engine overhaul is necessary.
Limit; 1000 kPa (145 psi)
6A–82
ENGINE MECHANICAL
4. Reinstall the rod caps (12) to their original
positions.
Tighten the rod cap nuts.
Torque: 54 Nꞏm (5.5 Kgꞏm/40 lb ft)
NOTE: Do not allow the crankshaft to rotate.
5. Remove the rod caps.
6. Measure the width of the plastigage and
determine the oil clearance. If the oil clearance
exceeds the limit, replace the rod bearing as a
set.
Standard : 0.019 mm–0.043 mm
(0.0007 in–0.0017 in)
Limit : 0.08 mm (0.003 in)
015RS008
7. Clean the plastigage from the bearings and the
crankshaft pins.
Con–rod Bearing Selection
Select and install the new connecting rod bearings,
paying close attention to the connecting rod big end
diameter size mark (1).
NOTE: Take care not to confuse the alignment mark (2)
and the size mark (1) during the installation procedure.
015RS034
1 Size MarkBig end Bore
DiameterCrankshaft Pin
DiameterConnecting Rod
Bearing Thickness
(Reference)Color of
Size
MarkOil Clearance
(Reference)
A56.994-57.000
(2.2439-2.2441)1.512-1.516
(0.0595-0.0597)Ye l l o w0.025-0.054
(0.0010-0.0021)
B56.988-56.994
(2.2436-2.2439)53.922-53.937
(2.1229-2.1235)1.508-1.512
(0.0594-0.0595)Green0.027-0.056
(0.0011-0.0022)
C56.982-56.988
(2.2434-2.2436)1.504-1.508
(0.0592-0.0594)Pink0.029-0.058
(0.0011-0.0023)
Reassembly
1. Install connecting rod
2. Install piston3. Install piston pinApply a thin coat of engine oil to the piston pin. Try to
insert the piston pin into the piston pin hole with
normal finger pressure.
NOTE: When changing piston / connecting rod
combinations, do not change the piston / piston pin
combination and do not reuse the old piston pin.