2004 TOYOTA 4RUNNER ECU

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HITCHES
If you wish to install a trailer hitch, you
should consult with your Toyota dealer.
Use only a hitch recommended by the
hitch manufacturer and the one which
conforms to the total trailer weight re-
quirement.
According to the hitch receiver type,
the maximum gross trailer weight and
hitch that can be used differs. Refer to
the above illustrations to confirm the
hitch receiver type for your vehicle.
If you wish to install an aftermarket
hitch, the hitch must be bolted securely
to the vehicle frame and installed ac-
cording to the hitch manufactures’ in-
structions.
The hitch ball and king pin should have
a light coat of grease.
Toyota recommends the ball mount as-
sembly be removed when not towing to
prevent injury and to prevent damage
in the event of a rear end collision.
After removing the ball mount assem-
bly, install the grommet to the hitch to
prevent entry of dirt and mud.
NOTICE
Do not install weight distributing
hitch to weight carrying hitch re-
ceiver because it will be damaged
your vehicle.
 Do not use axlemounted hitches as
they can cause damage to the axle
housing, wheel bearings, wheels or
tires. Also, never install a hitch
which may interfere with the normal
function of an Energy Absorbing
Bumper, if so equipped.
1 Trailer ball load rating
2 Ball diameter
3 Shank length
4 Shank diameter

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CAUTION
If the total trailer weight exceeds
453 kg (1000 lb.), trailer brakes are
required .
Never tap into your vehicle’s hy-
draulic system as it would lower its
braking effectiveness .
Never tow a trailer without using a
safety chain securely attached to
both the trailer and the vehicle. If
damage occurs to the coupling unit
or hitch ball, there is danger of the
trailer wandering over into another
lane.
SERVICE CONNECTOR FOR TOWING
BRAKE CONTROLLER
Your vehicle is equipped with a service
connector for the towing brake controller
as shown. Link the connector to the tow-
ing brake controller via the sub wire har-
ness stored in the glove box. The detailed
explanation of the sub wire harness circuit
is packed together with the sub wire har-
ness.
Be sure to position the towing brake con-
troller where it does not prevent the driver
from operating the pedal.
Toyota recommends that the sub wire har-
ness be stored in the glove box when it
is not in use. TIRES
Ensure that your vehicle’s tires are
properly inflated. See page 368 in Sec-
tion 7
−2 and page 394 in Section 8 for
instructions.
The trailer tires should be inflated to
the pressure recommended by the trail-
er manufacturer in respect to the total
trailer weight.

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DISCONNECTING A TRAILER (models
with rear height control air suspension)
Stop your vehicle and a trailer in line and
perform the following:
1. Put the rear height control air suspen- sion in the “LO” (low) mode. (Make
sure the vehicle height is in the “LO”
(low) mode by pushing the height se-
lect switch on the “ ” side.)
2. Turn the ignition switch off or push the “HEIGHT CONTROL OFF” switch to
turn off the rear height control air sus-
pension.
3. Set the supporting leg of a trailer on the ground and raise the hitch by 100
mm (4 in.).
4. Turn the ignition switch on or push the “HEIGHT CONTROL OFF” switch to
turn on the rear height control air sus-
pension.
5. Wait for about 20 seconds until the rear vehicle height is lowered by the
automatic leveling function.
6. Make sure the hitch is disconnected. If not, raise the hitch higher and repeat
steps 2 through 5. 7. Move the vehicle forward in the “LO”
(low) mode where the hitch does not
touch anything in the “N” (normal)
mode.
8. Put the rear height control air suspen- sion in the “N” (normal) mode.
PRETOWING SAFETY CHECK
Check that your vehicle remains level
when a loaded or unloaded trailer is
hitched. Do not drive if the vehicle has
an abnormal nose −up or nose −down
condition, and check for improper
tongue load, overload, worn suspension
or other possible causes.
Make sure the trailer cargo is securely
loaded so that it cannot shift.
Check that your rear view mirrors con-
form to any applicable federal, state/
provincial or local regulations. If not,
install the rear view mirrors required
for towing purpose. TRAILER TOWING TIPS
When towing a trailer, your vehicle will
handle differently than when not tow-
ing. The three main causes of vehicle
trailer accidents are driver error, exces-
sive speed and improper trailer loading.
Keep these in mind when towing:
Before starting out, check operation of
the lights and all vehicle
−trailer connec-
tions. After driving a short distance,
stop and recheck the lights and con-
nections. Before actually towing a trail-
er, practice turning, stopping and back-
ing with a trailer in an area away from
traffic until you learn the feel.
Backing with a trailer is difficult and
requires practice. Grip the bottom of
the steering wheel and move your hand
to the left to move the trailer to the
left. Move your hand to the right to
move the trailer to the right. (This pro-
cedure is generally opposite to that
when backing without a trailer.) Also,
just turn the steering wheel a little at
a time, avoiding sharp or prolonged
turning. Have someone guide you when
backing to reduce the risk of an acci-
dent.

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NOTICE
Do not continue driving with
a deflated tire. Driving even a
short distance can damage a
tire and wheel beyond repair.
 Vehicles with rear height con-
trol air suspension: When
jacking up or insta lling the
tire chains, be sure to turn
off the rear height control
and stop the engine. Other-
wise, the vehicle height may
change in the automatic lev-
eling function, resulting in
accident.
1. G et th e req u i red to o l s an d
spare tire.
1. Tool bag
2. Jack
To prepare yourself for an emergency,
you should familiarize yourself with
the use of the jack, each of the tools
and their storage locations.
When storing the tool bag, make sure
it is securely held by the tightening
strap.Turn the jack joint by hand.
To rem ov e: Tur n the joint in direction
1 until the jack is free.
To store: Turn the joint in direction 2
until the jack is fi rmly secured to pre-
vent it flying forward during a collision
or sudden braking.
— R eq u ired to o ls an d sp are
tire

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To remove the spare tire under the
luggage compartment:
1. Put a jack handle and jack handle extensions together as shown in
the illustration.
1. Jack handle extensions
2. Jack handleWhen connecting the jack handle ex-
tensions, use the jack handle to tight-
en the square head bolt. Make sure
that the bolt fits into the depression
on the joint.
When connecting the jack handle ex-
tension with the jack handle, tighten
the round head bolt by hand.
NOTICE
Tighten the square head bolt
securely. Otherwise, the exten-
sion may come off and it may
damage the paint or vehicle
body.
2. Insert the end of the jack handle
extension into the lowering screw
and turn it counterclockwise with
the handle.
3. After the tire is lowered completely to the ground, remove the holding
bracket.
When storing the spare tire, put it in
place with the outer side of the wheel
facing up. Then secure the tire, taking
care that the tire goes straight up
without catching on any other part, to
prevent it from flying forward during
a collision or sudden braking.

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2004 4RUNNER from Aug. ’03 Prod. (OM35811U)
When connecting the jack handle ex-
tension(s) and jack handle end, use
the jack handle to tighten the square
head bolt. Make sure that the bolt fits
into the depression on the joint.
When connecting the jack handle ex-
tension with the jack handle, tighten
the round head bolt by hand.
NOTICE
Tighten the square head bolt
securely. Otherwise, the exten-
sion may come off and it may
damage the paint or vehicle
body.
Front of
vehicle
6. After making sure that no one is in the vehicle, as the jack
touches the vehicle and begins
to fit, doublecheck that it is
properly positioned.
Rear side only—
When positioning the jack under the
rear axle housing, make sure the
groove on the top of the jack fits with
the rear axle housing.
7. Raise the vehicle high enough so that the spare tire can be
installed.
Remember you will need more ground
clearance when putting on the spare
tire than when removing the flat tire.
To raise the vehicl e, insert the jack
handle end into the jack (it is a loose
fit) and turn it clockwise with the han-
dle.
—Raising your vehicle

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9. Reinstall all the wheel nuts fin-
ger tight.
Reinstall the wheel nuts (tapered end
inward) and tighten them as much as
you can by hand. Press back on the
tire back and see if you can tighten
them more.
CAUTION
Never use oil or grease on the
bolts or nuts. Doing so may lead
to overtightening the nuts and
damaging the bolts. The nuts
may loose and the wheels may
fall off, which could cause a seri-
ous accident. If there is oil or
grease on any bolt or nut, clean
it.
10.Lower the vehicle completely and tighten the wheel nuts.
Turn the jack handle extension coun-
terclockwise with handle to lower the
vehicle.
Use only the wheel nut wrench and
turn it clockwise to tighten the nuts.
Do not use other tools or any addition-
al leverage other than your hands,
such as a hammer, pipe or your foot.
Make sure the wrench is securely en-
gaged over the nut.
Tighten each nut a little at a time in
the order shown. Repeat the process
until all the nuts are tight.
—Reinstalling wheel nuts —Lowering your vehicle

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CAUTION
When lowering the vehicle,
make sure all portions of your
body and all other persons
around will not be injured as
the vehicle is lowered to the
ground.
 Have the wheel nuts tightened
with torque wrench to 110 N·m
(11.5 kgf·m, 83 ft·lbf), as soon
as possible after changing
wheels. Otherwise, the nuts
may loosen and the wheels
may fall off, which could cause
a serious accident.
11. Reinstall the wheel ornament.
Put the wheel ornament into position
and then tap it firmly with the side or
heel of your hand to snap it into place.
CAUTION
Take due care in handling the or-
nament to avoid unexpected per-
sonal injury.
12.Check the air pressure of the re-
placed tire.
Adjust the air pressu re to the specifi-
cation designated on page 394 in
Section 8. If the pressure is lower,
drive slowly to the nearest service
station and fill to the correct pressure.
Do not forget to reinstall the tire infla-
tion valve cap as dirt and moisture
could get into th e valve core and
possibly cause air leakage. If the cap
is missing, have a new one put on as
soon as possible.
13.Restow all the tools, jack and flat tire securely.
As soon after changing wheels as
possible, tighten the wheel nuts to the
torque specified on page 394 in Sec-
tion 8 with a torque wrench. Have a
technician repair the flat tire.
—Reinstalling wheel ornament —After changing wheels