2004 TOYOTA 4RUNNER ECU

’04 4Runner_U (L/O 0308)
334
2004 4RUNNER from Aug. ’03 Prod. (OM35811U)
NOTICE
Only use specified towing eyelet;
otherwise your vehicle may be dam-
aged.
 Never tow a vehicle from the rear
with four wheels on the ground.
This may cause serious damage to
the transmission.
A driver must be in the vehicle to steer
it and operate the brakes.
Towing in this manner may be done only
on hard− surfaced roads for a short dis-
tance and at low speeds. Also, the
wheels, axles, drive train, steering and
brakes must all be in good condition.
CAUTION
Use extreme caution when towing ve-
hicles. Avoid sudden starts or erratic
driving maneuvers which would place
excessive stress on the emergency
towing eyelet and towing cable or
chain. The eyelet and towing cable or
chain may break and cause serious
injury or damage.
NOTICE
Use only a cable or chain specifically
intended for use in towing vehicles.
Securely fasten the cable or chain to
the towing eyelet provided.
Before towing, release the parking brake
and put the transmission in “N”. The key
must be in “ACC” (engine off) or “ON”
(engine running).
Four −wheel drive models—On multi −mode
four −wheel drive models, put the multi −
mode control switch knob in “H2”. On full −
time four −wheel drive models, unlock the
center differential.
CAUTION
If the engine is not running, the pow-
er assist for the brakes and steering
will not work so steering and braking
will be much harder than usual.
Before emergency towing, check that
the eyelet is not broken or damaged
and that the installation bolts are not
loose.
Fasten the towing cable or chain se-
curely to the eyelet.
Do not jerk the eyelet. Apply steady
and even force.
To avoid damaging the eyelet, do not
pull from the side or at a vertical
angle. Always pull straight ahead.
—Emergency towing eyelet
precautions

’04 4Runner_U (L/O 0308)
348
2004 4RUNNER from Aug. ’03 Prod. (OM35811U)
Power steering fluid level
Check the level through the reservoir. The
level should be in the “HOT” or “COLD”
range depending on the fluid temperature.
See page 365 in Section 7 −2 for addition-
al information.
Exhaust system
If you notice any change in the sound of
the exhaust or smell exhaust fumes, have
the cause located and corrected immedi-
ately. (See “Engine exhaust cautions” on
page 275 in Section 2.)
INSIDE THE VEHICLE
Items listed below should be checked
regularly, e.g. while performing periodic
services, cleaning the vehicle, etc.
Lights
Make sure the headlights, stop lights, tail
lights, turn signal lights, and other lights
are all working. Check headlight aim.
Service reminder indicators and warning
buzzers
Check that all service reminder indicators
and warning buzzers function properly.
Steering wheel
Check that it has the specified free play.
Be alert for changes in steering condition,
such as hard steering or strange noise. Seats
Check that all front seat controls such as
seat adjusters, seatback recliner, etc. op-
erate smoothly and that all latches lock
securely in any position. Check that the
head restraint move up and down smooth-
ly and that the locks hold securely in any
latched position. For folding
−down rear
seatbacks and swing −up rear seat cush-
ions (vehicles without third seats), tum-
bling second seats (vehicles with third
seats), folding −up third seats and detach-
able third seats, check that the latches
lock securely.
Seat belts
Check that the seat belt system such as
buckles, retractors and anchors operate
properly and smoothly. Make sure that the
belt webbing is not cut, frayed, worn or
damaged.
Accelerator pedal
Check the pedal for smooth operation and
uneven pedal effort or catching.
Brake pedal
Check the pedal for smooth operation and
that the pedal has the proper clearance.
Check the brake booster function. Brakes
At a safe place, check that the brakes do
not pull to one side when applied.
Parking brake
Check that the pedal has the proper travel
and that, on a safe incline, your vehicle
is held securely with only the parking
brake applied.
Automatic transmission “Park” mecha-
nism
On a safe incline, check that your vehicle
is held securely with the selector lever in
“P” position and all brakes released.
OUTSIDE THE VEHICLE
Items listed below should be performed
from time to time, unless otherwise
specified.
Fluid leaks
Check underneath for leaking fuel, oil, wa-
ter or other fluid after the vehicle has
been parked for a while. If you smell fuel
fumes or notice any leak, have the cause
found and corrected immediately.

’04 4Runner_U (L/O 0308)
349
2004 4RUNNER from Aug. ’03 Prod. (OM35811U)
Doors and engine hood
Check that all doors including back door
operate smoothly and all latches lock se-
curely. Make sure the engine hood sec-
ondary latch secures the hood from open-
ing when the primary latch is released.
Tire inflation pressure
Check the pressure with a gauge ev-
ery two weeks, or at least once a
month. See page 368 in Section 7 −2
for additional information.
Tire surface and wheel nuts
Check the tires carefully for cuts,
damage or excessive wear. See page
370 in Section 7− 2 for additional in-
formation. When checking the tires,
make sure no nuts are missing, and
check the nuts for looseness. Tighten
them if necessary.
Tire rotation
Rotate the tires according to the
maintenance schedule. (For sched-
uled maintenance information, please
refer to the “Scheduled Maintenance
Guide” or “Owner ’s Manual Supple-
ment”.) See page 372 in Section 7 −2
for additional information.
Be on the alert for changes in perfor-
mance, sounds, and visual tip −offs that
indicate service is needed. Some impor-
tant clues are as follows:
Engine missing, stumbling, or pinging
Appreciable loss of power
Strange engine noises
A leak under the vehicle (however, wa-
ter dripping from the air conditioning
after use is normal.)
Change in exhaust sound (This may
indicate a dangerous carbon monoxide
leak. Drive with the windows open and
have the exhaust system checked im-
mediately.)
Flat −looking tire; excessive tire squeal
when cornering; uneven tire wear
Vehicle pulls to one side when driving
straight on a level road
Strange noises related to suspension
movement
Loss of brake effectiveness; spongy
feeling brake pedal; pedal almost
touches floor; vehicle pulls to one side
when braking
Engine coolant temperature continually
higher than normal If you notice any of these clues, take your
vehicle to your Toyota dealer as soon as
possible. It probably needs adjustment or
repair.
CAUTION
Do not continue driving with the ve-
hicle unchecked. It could result in se-
rious vehicle damage and possibly
personal injury.
Does your vehicle need
repairing?

’04 4Runner_U (L/O 0308)
395
2004 4RUNNER from Aug. ’03 Prod. (OM35811U)
Engine compartment
Fuses (type A)
1. SPARE 10 A: Spare fuse
2. SPARE 15 A: Spare fuse
3. STOP 10 A: Stop/tail lights, high
mounted stoplight, shift lock control
system, anti −lock brake system, trac-
tion control system (two −wheel drive
models), active traction control system
(four −wheel drive models), vehicle sta-
bility control system, rear height control
air suspension, multiport fuel injection
system/s equential multiport fuel injec-
tion system, trailer brake controller,
trailer lights (tail lights)
Instrument panel
4. AC115V INV 15 A: AC inverter
5. FR FOG 15 A: Front fog lights
6. OBD 7.5 A: On−board diagnosis sys-
tem
7. HEAD (LO RH) 10 A: Right −hand
headlight (low beam)
8. HEAD (LO LH) 10 A: Left−hand head-
light (low beam)
9. HEAD (HI RH) 10 A: Right −hand head-
light (high beam)
10. HEAD (HI LH) 10 A: Left −hand head-
light (high beam) 11. EFI NO.2 10 A:
Multiport fuel injection
system/s equential multiport fuel injec-
tion system
12. HEATER NO.2 7.5 A: Air conditioning
system
13. AIRSUS NO.2 10 A: Rear height con-
trol air suspension
14. SEAT HEATER 25 A: Seat heaters
15. DEFOG 30 A: Back window defogger,
multiport fuel injection system/sequen-
tial multiport fuel injection system
16. MIR HEATER 10 A: Outside rear view
mirror heater
17. DOME 10 A: Interior light, personal
lights, wireless remote control system,
door courtesy lights, rear seat audio
system, gauge and meter, vanity lights,
instrument panel lights, running board
lights, multiplex communication system
18. RADIO NO.1 20 A: Audio system, nav-
igation system
19. ECUB 10 A: Anti−lock brake system,
navigation system, traction control sys-
tem (two −wheel drive models), active
traction control system (four −wheel
drive models), vehicle stability control
system, air c onditioning system, multi-
plex communication system, theft deter-
rent system
Fuses

’04 4Runner_U (L/O 0308)
396
2004 4RUNNER from Aug. ’03 Prod. (OM35811U)
20. ALTS 7.5 A: Charging system
21. HORN 10 A: Horns
22. A/F HEATER 15 A: A/F sensor
23. TRNHAZ 15 A: Turn signal lights,
emergency flashers
24. ETCS 10 A: Multiport fuel injection
system/s equential multiport fuel injec-
tion system
25. EFI 20 A: Multiport fuel injection sys-
tem/sequential multiport fuel injection
system
26. DR/LCK 20 A: Power door lock system
27. TOWING 30 A: Towing converter
28. RADIO NO.2 20 A: Audio system
29. IGN 10 A: Multiport fuel injection sys-
tem/sequential multiport fuel injection
system, anti −lock brake system, trac-
tion control system (two −wheel drive
models), active traction control system
(four −wheel drive models), vehicle sta-
bility control system, stop light, meter
and gauge
30. SRS 10 A: SRS airbag system
31. GAUGE 7.5 A: Meter and gauge
32. STA NO.2 7.5 A: Multiport fuel injec-
tion system/sequential multiport fuel in-
jection system 33. FR WIPWSH 30 A:
Windshield wipers
and washer
34. 4WD 20 A: Four−wheel drive control
system
35. D P/SEAT 30 A: Driver ’s power seat
36. P P/SEAT 30 A: Front passenger ’s
power seat
37. PWR OUTLET 15 A: Power outlets
38. RR WSH 15 A: Back window washer,
multiplex communication system
39. ECUIG 10 A: Shift lock control sys-
tem, power windows, anti −lock brake
system, traction control system (two −
wheel drive models), active traction
control system (four −wheel drive mod-
els), vehicle stability control system,
electric moon roof, multiplex commu-
nication system, theft deterrent system,
rear height control air suspension, tire
pressure warning system 40. IG1 15 A:
Anti−lock brake system,
traction control system (two −wheel
drive models), active traction control
system (four −wheel drive models), ve-
hicle stability control system, air condi-
tioning system, charging system, back
window defogger, back −up lights, turn
signal lights, emergency flashers, seat
heaters, AC inverter, instrument panel
light control, auto anti −glare inside rear
view mirror, SRS airbag system
41. STA 7.5 A: No circuit
42. SECU/HORN 10 A: Theft deterrent sys-
tem
4

3. TAIL 10 A: Tail lights, license plate
lights, parking lights, instrument panel
light control, multiport fuel injection
system/s equential multiport fuel injec-
tion system, instrument panel lights,
meter and gauge, grove box light
44. ACC 7.5 A: Power outlets, outside rear
view mirrors, audio system, navigation
system, rear seat audio system, shift
lock control system, instrument panel
lights
45. CIG 10 A: No circuit

’04 4Runner_U (L/O 0308)
397
2004 4RUNNER from Aug. ’03 Prod. (OM35811U)
Fuses (type B)
46. AIRSUS 50 A: Rear height control air
suspension
47. AM1 50 A: All components in “ACC”,
“CIG”, “IG1”, “ECU −IG”, “FR WIP −
WSH”, “RR WIP”, “RR −WSH”, “4WD”,
and “STA” fuses
48. TOWING BRK 30 A: Trailer brake con-
troller
49. J/B 50 A: All components in “PWR
OUTLET”, “D P/SEAT”, “P P/SEAT”,
“POWER”, “TAIL” and “SECU/HORN”
fuses
50. BATT CHG 30 A: Trailer sub battery
51. TOWING 40 A: Trailer lights (tail
lights)
52. ABS MTR 40 A: Anti−lock brake sys-
tem, traction control system (two −wheel
drive models), active traction control
system (four −wheel drive models), ve-
hicle stability control system
53. AM2 30 A: Starter system, “IGN”,
“GAUGE”, “STA NO.2” and “SRS” fuses
54. ABS SOL 50 A: Anti−lock brake sys-
tem, traction control system (two −wheel
drive models), active traction control
system (four −wheel drive models), ve-
hicle stability control system 55. POWER 30 A:
Power windows, electric
moon roof
Fuses (type C)
56. ALT 140 A: All components in “AM2”,
“ALT −S”, “DR/LCK”, “TRN− HAZ”,
“HORN”, “RADIO NO.2”, “EFI”,
“TOWING”, “ABS MTR”, “ABS SOL”,
“HEATER” and “ETCS” fuses
57. HEATER 60 A: Air conditioning system