2003 TOYOTA TACOMA check engine

’03 Tacoma U (L/O 0209)
1212003 MY TACOMA (OM35800U)
(a) Brake System Warning Light
This light comes on in the following cases
when the ignition key is in the “ON” posi-
tion.
When the parking brake is applied...
When the brake fluid level is low...
CAUTION
It is dangerous to continue driving
normally when the brake fluid level is
low.
Have your vehicle checked at your
Toyota dealer in the following case:
The light does not come on even if the
parking brake is applied when the igni-
tion key is in the “ON” position.
CAUTION
If the light does not turn off even
after the parking brake is released
while the engine is running, immedi-
ately stop your vehicle at a safe
place and contact your Toyota dealer.
In this case, the brakes may not work
properly and your stopping distance
will become longer. Depress the brake
pedal firmly and bring the vehicle to
an immediate stop.
(b) Seat Belt Reminder Light and Buzz-er
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 comes on if the driver’s seat belt
is not fastened. Unless the driver fastens
the belt, the light stays on and the buzzer
sounds for about 4 to 8 seconds.
(c) 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.
(d) 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.

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1222003 MY TACOMA (OM35800U)
NOTICE
Do not drive the vehicle with the
warning light on—even for one block.
It may ruin the engine.
(e) 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, auto-
matic transmission electrical system or
warning light system itself.
Contact your Toyota dealer as soon as
possible to service the vehicle.
Fourwheel drive models and Pre Runner
with 5VZFE engine only—
If the engine speed does not increase with
the accelerator pedal depressed down to
about the middle position, there may be
a problem somewhere in your electronic
throttle control system.
At this time, if you depress the accelera-
tor pedal more firmly and slowly, you can
drive your vehicle at low speeds. Have
your vehicle checked by your Toyota deal-
er 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” in Section 6.
(f) 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.

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1242003 MY TACOMA (OM35800U)
(j) Automatic Transmission Fluid Tem-perature Warning Light
This light warns that the automatic trans-
mission fluid temperature is too high.
If this light comes on while you are driv-
ing, slow down and pull off the road. Stop
the vehicle at a safe place and put the
selector lever in “P”. With the engine id-
ling, wait until the light goes off. If the
light goes off, you may start the vehicle
again. If the light does not go off, call a
Toyota dealer or qualified repair shop for
assistance.
(k) Low Windshield Washer Fluid Level Warning Light (on some models)
The light warns that the windshield washer
fluid level is too low. Add washer fluid at
your earliest opportunity. (For instructions,
see “Adding washer fluid” in Section 73.)
(l) Key Reminder Buzzer
This buzzer reminds you to remove the
key when you open the driver ’s door with
the ignition key in the “ACC” or “LOCK”
position. 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. Turn the ignition key to “ON”, but do not start the engine.
All the service reminder indicators
should come on. The “ABS” warning
light goes off after a few seconds. The
SRS warning light goes off after about
6 seconds.
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.

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1392003 MY TACOMA (OM35800U)
CAUTION
Do not lock the differential until the
wheels have stopped spinning.
Otherwise, the vehicle may move in
an unexpected direction when the
differential lock is engaged, result-
ing in an accident. This may also
lead to possible damage to differen-
tial lock component parts.
Do not drive over 8 km/h (5 mph)
when the differential is locked.
To unlock the differential, push the
switch once again.
Unlock the differential as soon as the ve-
hicle moves out.
For easy unlocking, slightly turn the steer-
ing wheel in either direction while the ve-
hicle is in motion.
When the differential lock is disengaged,
the indicator light will go out.
Except for Pre Runner models⎯
The differential will also unlock if you shift
the front drive control lever out of “L4”.
Never forget to turn off the switch after
using this feature.To check the indicator bulb, turn the igni-
tion key to the “ON” position, but do not
start the engine.
CAUTION
Do not keep driving with the differen-
tial lock switch on.
When parking, firmly apply the parking
brake to avoid inadvertent creeping.
To set: Pull out on the lever. For better
holding power, first depress the brake
pedal and hold it while setting the parking
brake.
To release: Press the lock release button
(1), turn the lever clockwise (2), then
push it in (3).
To remind you that the parking brake is
set, the parking brake reminder light in
the instrument panel remains on until you
release the parking brake.
Parking brake

’03 Tacoma U (L/O 0209)
1412003 MY TACOMA (OM35800U)
SETTING AT A DESIRED SPEED
On vehicles with automatic transmission,
the transmission must be in “D” before
you set the cruise control speed.
Bring your vehicle to the desired speed,
push the lever down in the “SET/COAST”
direction and release it. This sets the ve-
hicle at that speed. If the speed is not
satisfactory, tap the lever up for a faster
speed, or tap it down for a slower speed.
Each tap changes the set speed by 1.6
km/h (1.0 mph). You can now take your
foot off the accelerator pedal.If you need acceleration—for example,
when passing—depress the accelerator
pedal enough for the vehicle to exceed
the set speed. When you release it, the
vehicle will return to the speed set prior
to the acceleration.
CAUTION
For manual transmission:
While driving with the cruise control
on, do not shift to neutral without
depressing the clutch pedal, as this
may cause engine racing or overrev-
ving.
CANCELLING THE PRESET SPEED
You can cancel the preset speed by:
a. Pulling the lever in the “CANCEL”
direction and releasing it
b. Depressing the brake pedal
c. Depressing the clutch pedal (manual
transmission)
If the vehicle speed falls below about 40
km/h (25 mph), the preset speed will auto-
matically cancel out.
If the vehicle speed drops 16 km/h (10
mph) below the preset speed, the preset
speed will also automatically cancel out. If the preset speed automatically cancels
out other than for the above cases, have
your vehicle checked by your Toyota deal-
er at the earliest opportunity.
RESETTING TO A FASTER SPEED
Push the lever up in the “RES/ACC” direc-
tion and hold it. Release the lever when
the desired speed is attained. While the
lever is held up, the vehicle will gradually
gain speed.
However, a faster way to reset is to ac-
celerate the vehicle and then push the
lever down in the “SET/COAST” direction.
RESETTING TO A SLOWER SPEED
Push the lever down in the “SET/COAST”
direction and hold it. Release the lever
when the desired speed is attained. While
the lever is held down, the vehicle speed
will gradually decrease.
However, a faster way to reset is to de-
press the brake pedal and then push the
lever down in the “SET/COAST” direction.

’03 Tacoma U (L/O 0209)
1962003 MY TACOMA (OM35800U)
NOTICE
A large amount of unburned gases
flowing into the threeway catalytic
converter may cause it to overheat
and create a fire hazard. To prevent
this and other damage, observe the
following precautions:
Use only unleaded gasoline.
 Do not drive with an extremely low
fuel level; running out of fuel could
cause the engine to misfire, creat-
ing an excessive load on the three
way catalytic converter.
 Do not allow the engine to run at
idle speed for more than 20 minu-
tes.
 Avoid racing the engine.
 Do not pushstart or pullstart your
vehicle.
 Do not turn off the ignition while
the vehicle is moving.
Keep your engine in good running
order. Malfunctions in the engine
electrical system, electronic ignition
system/distributor ignition system
or fuel systems could cause an ex-
tremely high threeway catalytic
converter temperature.
 If the engine becomes difficult to
start or stalls frequently, take your
vehicle in for a checkup as soon
as possible. Remember, your Toyota
dealer knows your vehicle and its
threeway catalytic converter sys-
tem best.
 To ensure that the threeway cata-
lytic converter and the entire emis-
sion control system operate proper-
ly, your vehicle must receive the
periodic inspections required by the
Toyota Maintenance Schedule. For
scheduled maintenance information,
refer to the “Scheduled Maintenance
Guide” or “Owner ’s Manual Supple-
ment”.CAUTION
Avoid inhaling the engine exhaust.
It contains carbon monoxide, which
is a colorless and odorless gas. It
can cause unconsciousness or even
death.
Make sure the exhaust system has
no holes or loose connections. The
system should be checked from
time to time. If you hit something,
or notice a change in the sound of
the exhaust, have the system
checked immediately.
Do not run the engine in a garage
or enclosed area except for the
time needed to drive the vehicle in
or out. The exhaust gases cannot
escape, making this a particularly
dangerous situation.
Do not remain for a long time in a
parked vehicle with the engine run-
ning. If it is unavoidable, however,
do so only in an unconfined area
and adjust the heating or cooling
system to force outside air into the
vehicle.
Engine exhaust cautions

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1982003 MY TACOMA (OM35800U)
IMPORTANCE OF ENGINE OIL LEVEL
CHECK
One of the most important points in prop-
er vehicle maintenance is to keep the en-
gine oil at the optimum level so that oil
function will not be impaired. Therefore, it
is essential that the oil level be checked
regularly. Toyota recommends that the oil
level be checked every time you refuel
the vehicle.
NOTICE
Failure to check the oil level regularly
could lead to serious engine trouble
due to insufficient oil.
For detailed information on oil level check,
see “Checking the engine oil level” in Sec-
tion 72.
Your engine is fitted with twin ground
electrode spark plugs.
NOTICE
Use only twin ground electrode spark
plugs for your engine performance.
The tandem master cylinder brake system
is a hydraulic system with two separate
subsystems. If either subsystem should
fail, the other will still work. However, the
pedal will be harder to press, and your
stopping distance will be longer. Also, the
brake system warning light may come on.
CAUTION
Do not drive your vehicle with only a
single brake system. Have your
brakes fixed immediately.
BRAKE BOOSTER
The brake booster uses engine vacuum to
powerassist the brakes. If the engine
should quit while you are driving, you can
bring the vehicle to a stop with normal
pedal pressure. There is enough reserved
vacuum for one or two stops—but no
more!
Twin ground electrode spark
plugs (5VZFE engine) Brake system

’03 Tacoma U (L/O 0209)
1992003 MY TACOMA (OM35800U)
CAUTION
Do not pump the brake pedal if the
engine stalls. Each push on the
pedal uses up your reserved vacu-
um.
Even if the power assist is com-
pletely lost, the brakes will still
work. But you will have to push the
pedal hard, much harder than nor-
mal. And your braking distance will
be longer.
ANTILOCK BRAKE SYSTEM
(with “ABS” warning light)
The antilock brake system is designed
to help prevent lockup of the wheels
during a sudden braking or braking on
slippery road surfaces. This assists in
providing directional stability and steer-
ing performance of the vehicle under
these circumstances.
Effective way to press the ABS brake
pedal: When the antilock brake system
function is in action, you may feel the
brake pedal pulsating and hear a noise.
In this situation, to let the antilock
brake system work for you, just hold the
brake pedal down more firmly. Do not
pump the brake in a panic stop. This
will result in reduced braking performan-
ce.
The antilock brake system becomes op-
erative after the vehicle has accelerated
to a speed in excess of approximately 10
km/h (6 mph). It stops operating when the
vehicle decelerates to a speed below
approximately 5 km/h (3 mph).
Depressing the brake pedal on slippery
road surfaces such as on the manhole
cover, the steel plate under the construc-
tion, joints in the bridge, etc. on a rainy
day tends to activate the antilock brake
system.
You may hear a click or motor sound in
the engine compartment for a few seconds
when the engine is started or just after
the vehicle is started. This means that the
antilock brake system is in the self
check mode, and does not indicate a mal-
function. When the antilock brake system is ac-
tivated, the following conditions may
occur. They do not indicate a malfunc-
tion of the system:
You may hear the antilock brake sys-
tem operating and feel the brake pedal
pulsating and the vibrations of the ve-
hicle body and steering wheel. You
may also hear the motor sound in the
engine compartment even after the ve-
hicle is stopped.
At the end of the antilock brake sys-
tem activation, the brake pedal may
move a little forward.