2003 TOYOTA 4RUNNER check engine

’03 4Runner_U (L/O 0305)
33
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
If the battery becomes discharged due to
the vehicle being unused for a long time,
etc., when the battery is recharged or re-
placed, the system will give the alarm. If
this happens, immediately unlock any of
the side doors or the back door with the
key or the wireless remote control trans-
mitter, and the alarm will stop.
TESTING THE SYSTEM
1. Open all the windows.
2. Set the system as described above. The side doors and back door should
be locked with the key or wireless re-
mote control transmitter. Be sure to
wait until the indicator light goes off or
starts flashing.
3. Unlock any side door from the inside. The system should activate the alarm.
4. Stopping the alarm as described above.
5. Repeat this operation for the other doors and hood. When testing the
hood, also check that the system is
activated when the battery terminal is
disconnected and then reconnected.
If the system does not work properly,
have it checked by your Toyota dealer.
This indicates that the fuel filler door
is on the left side of your vehicle.1. To open the fuel filler door, pull the lever.
When refueling, turn off the engine.
CAUTION
Do not smoke, cause sparks or al-
low open flames when refueling.
The fumes are flammable.
When opening the cap, do not re-
move the cap quickly. In hot weath-
er, fuel under pressure could cause
injury by spraying out of the filler
neck if the cap is suddenly re-
moved.
Fuel tank cap

’03 4Runner_U (L/O 0305)
11 8
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
If the indicator or buzzer comes on...Do this.
(h)Replace engine oil.
(i)orTake vehicle to Toyota dealer. If brake system warning light is also on, stop
immediately and contact Toyota dealer.
(j)Take vehicle to Toyota dealer.
(k)Close all side doors and back door.
(l)Take vehicle to Toyota dealer immediately.
(m)Stop and check.

’03 4Runner_U (L/O 0305)
120
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
(a) Brake System Warning Light and
Buzzer
This light comes on in the following cases
when the ignition key is in the “ON” posi-
tion.
When the parking brake is applied...
This light comes on for a few seconds
when the ignition key is turned to the
“ON” position on even after the parking
brake is released.
When the brake fluid level is low...
CAUTION
It is dangerous to continue driving
normally when the brake fluid level is
low.
When the hydraulic brake booster
fails...
If the hydraulic booster causes a problem
resulting in poor braking performance, the
warning light comes on and buzzer sounds
continuously. Have your vehicle checked at your
Toyota dealer in the following cases:
The light does not come on even if the
parking brake is applied when the igni-
tion key is in the “ON” position.
The light does not come on even if the
ignition key is turned on with the park-
ing brake released.
A warning light turning on briefly during
operation does not indicate a problem.
CAUTION
If any of the following conditions oc-
curs, immediately stop your vehicle at
a safe place and contact your Toyota
dealer.
The light does not turn off even
after the parking brake is released
while the engine is running.
The warning buzzer comes on to-
gether with the warning light.
In either case, this can indicate that
the brakes may not work properly
and your stopping distance will be-
come longer. Depress the brake
pedal firmly and bring the vehicle
to an immediate stop.
The brake system warning light re-
mains on together with the “ABS”
warning light.
In this case, not only the antilock
brake system will fail but also the
vehicle will become extremely un-
stable during braking.
Any of the following conditions may oc-
cur, but do not indicate the malfunc-
tion:
The light may stay on for about 60
seconds after the ignition key is turned
to the “ON” position. It is normal if it
turns off after a while.
Depressing the brake pedal repeatedly
may turn on the warning light and
buzzer. It is normal if the light turns off
and the buzzer stops sounding after a
few seconds.
You may hear a small sound in the
engine compartment after the engine is
started or the brake pedal is depressed
repeatedly. This is a pump pulsating
sound of the brake system, and it is
not a malfunction.

’03 4Runner_U (L/O 0305)
121
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
(b) Driver’s Seat Belt Reminder Light
and Buzzer
This light and buzzer remind you to
buckle up the driver’s seat belt.
Once the ignition key is turned to “ON” or
“START”, the reminder light flashes and
buzzer come on if the driver’s seat belt
is not fastened. Unless the driver fastens
the belt, the light keeps on flashing and
the buzzer sounds for about 4 to 8 se-
conds.
(c) Front Passenger ’s Seat Belt Reminder Light
This light reminds you to buckle up the
front passenger ’s seat belt.
Once the ignition key is turned to “ON” or
“START”, the reminder light flashes if a
passenger sits in the front passenger seat
and does not fasten the seat belt. Howev-
er, if a front passenger uses an additional
seat cushion, the light may not flash even
when the seat belt is not buckled up.
If luggage or other load is placed on the
front passenger seat, depending on its
weight and how it is placed on the seat,
builtin sensors in the seat cushion may
detect the pressure, causing the reminder
light to come on. (d) Discharge Warning Light
This light warns that the battery is being
discharged.
If it comes on while you are driving, there
is a problem somewhere in the charging
system.
The engine ignition will continue to oper-
ate, however, until the battery is dis-
charged. Turn off the air conditioning,
blower, radio, etc., and drive directly to
the nearest Toyota dealer or repair shop.
NOTICE
Do not continue driving if the engine
drive belt is broken or loose.
(e) Low Engine Oil Pressure Warning
Light
This light warns that the engine oil pres-
sure is too low.
If it flickers or stays on while you are
driving, pull off the road to a safe place
and stop the engine immediately. Call a
Toyota dealer or qualified repair shop for
assistance.
The light may occasionally flicker when
the engine is idling or it may come on
briefly after a hard stop. There is no
cause for concern if it then goes out when
the engine is accelerated slightly.
The light may come on when the oil level
is extremely low. It is not designed to
indicate low oil level, and the oil level
must be checked using the level dipstick.
NOTICE
Do not drive the vehicle with the
warning light on—even for one block.
It may ruin the engine.

’03 4Runner_U (L/O 0305)
122
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
(f) Malfunction Indicator Lamp
This lamp comes on when the ignition
key is turned to the “ON” position and
goes off after the engine starts. This
means that the warning light system is
operating properly.
If the lamp remains on, or the lamp
comes on while driving, first check the
followings.
Empty fuel tank
If the fuel tank is empty, refuel immedi-
ately.
Loose fuel tank cap
If the fuel tank cap is loose, securely
tighten it.
These cases are temporary malfunctions.
The malfunction indicator lamp will go off
after taking several driving trips.
If the lamp will not go off even after the
several trips, contact your Toyota dealer
as soon as possible.
If the fuel tank is not empty or the fuel
tank cap is not loose...
There is a problem somewhere in the
engine, emission control system, elec-
tronic throttle control system, automatic
transmission electrical system or warn-
ing light system itself. Contact your Toyota dealer as soon as
possible to service the vehicle.
If the engine speed does not increase with
the accelerator pedal depressed down,
there may be a problem somewhere in
your electronic throttle control system.
At this time, vibration may occur. Howev-
er, if you depress the accelerator pedal
more firmly and slowly, you can drive your
vehicle at low speeds. Have your vehicle
checked by your Toyota dealer as soon as
possible.
Even if the abnormality of the electronic
throttle control system is corrected during
low speed driving, the system may not be
recovered until the engine is stopped and
the ignition key is turned to “ACC” or
“LOCK” position.
CAUTION
Be especially careful to prevent erro-
neous pedal operation.
Emissions inspection and maintenance
(I/M) programs
Your vehicle may not pass a state
emission inspection if the malfunction
indicator lamp remains on. Contact your
Toyota dealer to check your vehicle’s
emission control system and OBD
(OnBoard Diagnostics) system before
taking your vehicle for the inspection.
For details, see “Emissions Inspection and
Maintenance (I/M) programs” on page 314
in Section 6.
(g) Low Fuel Level Warning Light
This light comes on when the fuel level
in the tank becomes nearly empty. Fill up
the tank as soon as possible.
On inclines or curves, due to the move-
ment of fuel in the tank, the low fuel level
warning light may come on earlier than
usual.
(h) Engine Oil Replacement Reminder
Light (for vehicles sold in U.S.A.)
This light reminds you when to replace
the engine oil.
This light will come on when the ignition
key is turned to “ON” and will go off after
about a few seconds.

’03 4Runner_U (L/O 0305)
126
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
CHECKING SERVICE REMINDER
INDICATORS (except the low fuel level
warning light and low windshield
washer fluid level warning light)
1. Apply the parking brake.
2. Open one of the side doors or back door.
The open door warning light should
come on.
3. Close the door. The open door warning light should go
off.
4. Turn the ignition key to “ON”, but do not start the engine.
All the service reminder indicators ex-
cept the open door warning light should
come on.
The following service reminder indica-
tors go off after a few seconds:
Engine oil replacement reminder light
“ABS” warning light
“VSC TRAC” warning light
“TRAC OFF” indicator light
(twowheel drive models)
“VSC OFF” indicator light
(fourwheel drive models)
Slip indicator light
Height control indicator lights
Height control “OFF” indicator light
Downhill assist control system indicator
light (fourwheel drive models)
The SRS warning light goes off after
about 6 seconds.
There may be the case that the “ABS”
warning light (brake assist system
warning light), “VSC TRAC” warning
light and “TRAC OFF” (twowheel drive
models) or “VSC OFF” (fourwheel
drive models) indicator light stay on for
about 60 seconds after the ignition key
is turned to the “ON” position. It is
normal if they go out after a while.
If any service reminder indicator or warn-
ing buzzer does not function as described
above, have it checked by your Toyota
dealer as soon as possible.

’03 4Runner_U (L/O 0305)
145
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
If the “4LO” (low speed fourwheel drive)
indicator light continues to blink when you
operate the multimode control switch
knob to the “H4” or “L4” position, drive
forward or backward in a short distance,
then stop the vehicle completely, shift the
automatic transmission selector lever se-
curely into “N” and operate the switch
knob again.
If the indicator continues to blink even if
doing so, contact your Toyota dealer as
soon as possible. There may be a trouble
in the fourwheel drive system.
CAUTION
Never operate the multimode control
switch knob if the wheels are slip-
ping. Stop the slipping or spinning
before operating.
The traction control system automatical-
ly helps prevent the spinning of rear
wheels when the vehicle is started or
accelerated on slippery road surfaces.
When the ignition key is turned to “ON”,
the system automatically turns on.
CAUTION
Under certain slippery road condi-
tions, full traction of the vehicle and
power to the rear wheels cannot be
maintained, even though the traction
control system is in operation. Do not
drive the vehicle under any speed or
maneuvering conditions which may
cause the vehicle to lose traction
control. In situations where the road
surface is covered with ice or snow,
your vehicle should be fitted with
snow tires or tire chains. Always
drive at an appropriate and cautious
speed for the present road condi-
tions.
NORMAL DRIVING MODE
Leave the system on during ordinary
driving so that it can operate when
needed.
You may hear a sound in the engine
compartment for a few seconds when the
engine is started or just after the vehicle
begins to move. This means that the trac-
tion control system is in the selfcheck
mode, but does not indicate a malfunction.
When the traction control system is oper-
ating, the following conditions occur:
The system controls the spinning of the
rear wheels. At this time, the slip indi-
cator light blinks.
Traction control system
(twowheel drive models)

’03 4Runner_U (L/O 0305)
148
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
If the light comes on while driving, the
traction control system does not work.
However, as normal braking operates
when being applied, there is no problem
to continue your driving.
In the following cases, contact your Toyota
dealer:
The warning light does not come on
after the ignition key is turned to “ON”.
The warning light remains on after the
ignition key is turned to “ON”.
The warning light comes on while driv-
ing.
The “TRAC OFF” indicator light will come
on when the “VSC TRAC” warning light
comes on even if the “TRAC OFF” switch
is not pushed. The active traction control system auto-
matically helps prevent the spinning of
4 wheels when the vehicle is started or
accelerated on slippery road surfaces.
When the ignition key is turned to “ON”,
the system automatically turns on.
CAUTION
Under certain slippery road condi-
tions, full traction of the vehicle and
power to the 4 wheels cannot be
maintained, even though the traction
control system is in operation. Do not
drive the vehicle under any speed or
maneuvering conditions which may
cause the vehicle to lose traction
control. In situations where the road
surface is covered with ice or snow,
your vehicle should be fitted with
snow tires or tire chains. Always
drive at an appropriate and cautious
speed for the present road condi-
tions.
Leave the system on during the ordi-
nary driving so that it can operate
when needed.
You may hear a sound in the engine
compartment for a few seconds when the
engine is started or just after the vehicle
begins to move. This means that the ac-
tive traction control system is in the self
check mode, but does not indicate a mal-
function.
When the active traction control system is
operating, the following conditions occur:
The system controls the spinning of the
4 wheels. At this time, the slip indica-
tor light blinks.
Active traction control system
(fourwheel drive models)