2004 TOYOTA TUNDRA check engine light

’04 TUNDRA_U (L/O 0309)
155
2004 TUNDRA from Sep. ’03 Prod. (OM34426U)
(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...
With the vehicle stability control system—
This light comes on for a few seconds
when the ignition key is turned to the
“ON” position 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 (with the vehicle stability con-
trol system)...
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.
With the vehicle stability control system—
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
Without the vehicle stability control
system—
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.
With the vehicle stability control sys-
tem—
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.

’04 TUNDRA_U (L/O 0309)
157
2004 TUNDRA from Sep. ’03 Prod. (OM34426U)
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.
(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.
5VZ− FE engine—
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.

’04 TUNDRA_U (L/O 0309)
158
2004 TUNDRA from Sep. ’03 Prod. (OM34426U)
CAUTION
Be especially careful to prevent erro-
neous pedal operation.
2UZ−FE engine—
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
(On −Board Diagnostics) system before
taking your vehicle for the inspection.
For details, see “Emissions Inspection and
Maintenance (I/M) programs” 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) “ABS” Warning Light
Vehicles without vehicle stability control
system—
The light comes on when the ignition key
is turned to the “ON” position. If the anti
−
lock brake system works properly, the
light turns off after a few seconds. There-
after, if the system malfunctions, the light
comes on again.
When the “ABS” warning light is on (and
the brake system warning light is off), the
anti −lock brake system does not operate,
but the brake system still operates con-
ventionally.
When the “ABS” warning light is on (and
the brake system warning light is off), the
anti −lock brake system does not operate
so that the wheels could lock up during
a sudden braking or braking on slippery
road surfaces.

’04 TUNDRA_U (L/O 0309)
161
2004 TUNDRA from Sep. ’03 Prod. (OM34426U)
(m) Automatic Transmission Fluid
Temperature Warning Light
(fourwheel drive models)
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.
(n) Low Windshield Washer Fluid Level Warning Light
This light warns that the windshield wash-
er fluid level is too low. Add washer fluid
at your earliest opportunity. (For instruc-
tions, see “Adding washer fluid” in Section
7 −3.)
(o) 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. (p) Fourwheel Drive System Warning
Buzzer
This buzzer reminds you that the transfer
mode is not selected correctly.
If the buzzer sounds when you shift the
transfer from “2WD” to “4HI”, “4LO” to
“4HI”, “4HI” to “4LO”, or “4LO” to “2WD”
mode, follow the instructions in “Four −
wheel drive system” in Section 1 −7. 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 doors. 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 “ACC”. The SRS warning light should come on.
It goes off after about 6 seconds.
5. Turn the ignition key to “ON”, but do not start the engine.
All the service reminder indicators ex-
cept the open door warning light and
SRS warning light should come on.
The following service reminder indica-
tors go off after a few seconds:
“ABS” warning light
“VSC TRAC” warning light
“AUTO LSD” indicator light

’04 TUNDRA_U (L/O 0309)
177
2004 TUNDRA from Sep. ’03 Prod. (OM34426U)
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 trac-
tion control system is in the self −check
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 (two −wheel drive models)
or 4 wheels (four −wheel drive models).
At this time, the slip indicator light
blinks.
You may feel vibration or noise in your
vehicle, caused by operation of the
brakes. This indicates the system is
functioning properly.
The slip indicator light comes on for a few
seconds when the ignition key is turned
to “ON”. If the indicator light does not
come on when the ignition is turned on,
contact your Toyota dealer.
Ty p e A
Ty p e B
“VSC TRAC” warning light
This light warns that there is a problem
somewhere in the following.
Traction control system
Vehicle stability control system
“AUTO LSD” system
When the system is normal and the igni-
tion key is turned to “ON”, the warning
light will come on and will go off after a
few seconds.
It is not a malfunction that the warning
light may stay on for 60 seconds after the
ignition key is turned to “ON”.
Depressing the brake pedal repeatedly
may turn on the light. It is normal if it
goes out after a few seconds.
The brake actuator temperature increases
during continuous operation of the above
mentioned systems such as on slippery
roads. If the brake actuator temperature
becomes too high while any of the sys-
tems is operating, a buzzer will start to
sound intermittently to indicate that the
traction control system can no longer op-
erate. In this case, immediately stop your
vehicle at a safe place.

’04 TUNDRA_U (L/O 0309)
181
2004 TUNDRA from Sep. ’03 Prod. (OM34426U)
NOTICE
Do not drive with the “AUTO LSD”
switch continuously turned on.
The vehicle stability control system
helps provide integrated control of the
systems such as antilock brake sys-
tem, traction control, engine control,
etc. This system automatically controls
the output of the brakes or engine to
help prevent the vehicle from skidding
when cornering on a slippery road sur-
face or operating steering wheel abrupt-
ly.
The vehicle stability control activates
when the vehicle speed is more than 15
km/h (9 mph).
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 sys-
tem is in the self −check mode, but does
not indicate a malfunction.CAUTION
Do not rely excessively on the ve-
hicle stability control system. Even
if the vehicle stability control sys-
tem is operating, you must always
drive carefully and attentively to
avoid serious injury. Reckless driv-
ing will result in an unexpected ac-
cident. If the slip indicator light
blinks and an alarm sounds, special
care should be taken while driving.
Only use tires of specified size. The
size, manufacturer, brand and tread
pattern for all 4 tires should be the
same. If you use the tires other
than specified, or different type or
size, the vehicle stability control
system may not function correctly.
When replacing the tires or wheels,
contact your Toyota dealer. (See
“Checking and replacing tires” in
Section 72.)
Vehicle stability control
system

’04 TUNDRA_U (L/O 0309)
326
2004 TUNDRA from Sep. ’03 Prod. (OM34426U)
BRAKE BOOSTER (with the vehicle sta-
bility control system)
The brake booster uses brake fluid pres-
surized by the pump to power −assist the
brakes. If the brake booster fails during
driving, the brake system warning light
comes on and buzzer sounds continuous-
ly. In this case, the brakes may not work
properly. If they do not work well, depress
the brake pedal firmly. If the brake system
warning light comes on, immediately stop
your vehicle and contact your Toyota deal-
er.
The brake system warning light may stay
on for about 60 seconds after the ignition
key is turned to the “ON” position. It is
normal if the light turns off after a while.
Depressing the brake pedal repeatedly
may turn on the brake system 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.CAUTION
Do not pump the brake pedal if the
engine stalls. Each push on the
pedal uses up your brake fluid
pressure reserve.
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
increase.
ANTILOCK BRAKE SYSTEM (without
the vehicle stability control system)
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 anti −lock brake system
function is in action, you may feel the
brake pedal pulsating and hear a noise.
In this situation, to let the anti −lock
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 anti −lock 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 a manhole cov-
er, a steel plate at a construction site,
joints in a bridge, etc. on a rainy day
tends to activate the anti −lock brake sys-
tem.
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 begins to move. This means
that the anti −lock brake system is in the
self −check mode, and does not indicate a
malfunction.

’04 TUNDRA_U (L/O 0309)
331
2004 TUNDRA from Sep. ’03 Prod. (OM34426U)
Either of the following conditions may
occur, but do not indicate a 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 light. It is normal if it
turns off after about a few seconds. BRAKE ASSIST SYSTEM (with the ve-
hicle stability control system)
When you slam the brakes on, the
brake assist system judges as an emer-
gency stop and provides more powerful
braking for a driver who cannot hold
down the brake pedal firmly.
When you slam the brakes on, more pow-
erful braking will be applied. At this time,
you may hear a sound in the engine
compartment and feel the vibrations of the
brake pedal. This does not indicate a mal-
function.
The brake assist system becomes opera-
tive 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).
For an explanation of this system’s warn-
ing light, see “Service reminder indicators
and warning buzzers” in Section 1
−6.
The brake pad wear limit indicators on
your disc brakes give a warning noise
when the brake pads are worn to where
replacement is required.
If you hear a squealing or scraping noise
while driving, have the brake pads
checked and replaced by your Toyota
dealer as soon as possible. Expensive ro-
tor damage can result if the pads are not
replaced when necessary.
Brake pad wear limit
indicators