2021 TOYOTA AVALON HYBRID ECU

4527-2. Steps to take in an emergency
The following may indicate a problem with your transmission. Contact
your Toyota dealer or commercial towing service before towing.
●The hybrid system warning message is shown on the multi-informa-
tion display and the vehicle does not move.
●The vehicle makes an abnormal sound.
NOTICE
■To prevent damage to the vehicle when towing using a wheel-lift type
truck
●Do not tow the vehicle from the rear when the power switch is off. The
steering lock mechanism is not strong enough to hold the front wheels
straight.
●When raising the vehicle, ensure adequate ground clearance for towing at
the opposite end of the raised vehicle. Without adequate clearance, the
vehicle could be damaged while being towed.
■To prevent damage to the vehicle when towing with a sling-type truck
Do not tow with a sling-type truck, either from the front or rear.
■To prevent damage to the vehicle during emergency towing
Do not secure cables or chains to the suspension components.
Situations when it is necessary to contact dealers before towing
Towing with a wheel-lift type truck
From the frontFrom the rear
Release the parking brake.
Turn automatic mode off.
(P. 212)Use a towing dolly under the
front wheels.

4607-2. Steps to take in an emergency
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact
sensors, side impact sensors (front door), side impact sensors (front), side
impact sensors (rear), driver’s seat position sensor, driver’s seat belt buckle
switch, front passenger occupant classification system (ECU and sensors),
“AIR BAG ON” indicator light, “AIR BAG OFF” indicator light, seat belt preten-
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■Front passenger detection sensor, seat belt reminder and warning
buzzer
●If luggage is placed on the front passenger seat, the front passenger detec-
tion sensor may cause the warning light to flash and the warning buzzer to
sound even if a passenger is not sitting in the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger,
and the warning light may not operate properly.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving trips.
If the light does not go off even after several trips, contact your Toyota dealer
as soon as possible.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage tempo-
rarily drops, the electric power steering system warning light may come on
and the warning buzzer may sound.

4737-2. Steps to take in an emergency
7
When trouble arises
Lift up the hook of the luggage
floor cover on the trunk floor.
Secure the luggage floor cover
using the hook provided.
Remove the jack.
Lift up the hook of the luggage
floor cover on the trunk floor.
Taking out the jack
1
2
3
Taking out the spare tire
1

4747-2. Steps to take in an emergency
Secure the luggage floor cover
using the hook provided.
Remove the tool tray.
Loosen the center fastener that
secures the spare tire.
When taking out or stowing the
spare tire, make sure to firmly
hold opposite end of the tire.
2
3
4
WARNING
■When storing the spare tire
Be careful not to catch fingers or other body parts between the spare
tire and the body of the vehicle.

4807-2. Steps to take in an emergency
WARNING
■When using the compact spare tire
●Remember that the compact spare tire provided is specifically
designed for use with your vehicle. Do not use your compact spare tire
on another vehicle.
●Do not use more than one compact spare tires simultaneously.
●Replace the compact spare tire with a standard tire as soon as possi-
ble.
●Avoid sudden acceleration, abrupt steering, sudden braking and shift-
ing operations that cause sudden engine braking.
■When the compact spare tire is attached
The vehicle speed may not be correctly detected, and the following sys-
tems may not operate correctly:
*: If equipped
■Speed limit when using the compact spare tire
Do not drive at speeds in excess of 50 mph (80 km/h) when a compact
spare tire is installed on the vehicle.
The compact spare tire is not designed for driving at high speeds. Fail-
ure to observe this precaution may lead to an accident causing death or
serious injury.
■After using the tools and jack
Before driving, make sure all the tools and jack are securely in place in
their storage location to reduce the possibility of personal injury during a
collision or sudden braking.
• ABS & Brake assist
• VSC
•TRAC
• EPS
• Automatic High Beam
• Dynamic radar cruise control
with full-speed range
• LDA (Lane Departure Alert with
steering control)
• PCS (Pre-Collision System)• Tire pressure warning system
• BSM (Blind Spot Monitor)
•Intuitive parking assist*
• Intelligent Clearance Sonar
(ICS)
*
• Rear view monitor system*
• Toyota parking assist monitor
• Panoramic view monitor
*
• Navigation system*

4907-2. Steps to take in an emergency
■Starting the hybrid system when the 12-volt battery is discharged
The hybrid system cannot be started by push-starting.
■To prevent 12-volt battery discharge
●Turn off the headlights and the audio system while the hybrid system is off.
●Turn off any unnecessary electrical components when the vehicle is running
at a low speed for an extended period, such as in heavy traffic.
■When the 12-volt battery is removed or discharged
●Information stored in the ECU is cleared. When the 12-volt battery is
depleted, have the vehicle inspected at your Toyota dealer.
●Some systems may require initialization. (P. 535)
■When removing the 12-volt battery terminals
When the 12-volt battery terminals are removed, the information stored in the
ECU is cleared. Before removing the 12-volt battery terminals, contact your
Toyota dealer.
■Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gradually even when
the vehicle is not in use, due to natural discharge and the draining effects of
certain electrical appliances. If the vehicle is left for a long time, the 12-volt
battery may discharge, and the hybrid system may be unable to start. (The
12-volt battery recharges automatically while the hybrid system is operating.)
■When recharging or replacing the 12-volt battery
●In some cases, it may not be possible to unlock the doors using the smart
key system when the 12-volt battery is discharged. Use the wireless remote
control or the mechanical key to lock or unlock the doors.
●The hybrid system may not start on the first attempt after the 12-volt battery
has recharged but will start normally after the second attempt. This is not a
malfunction.
●The power switch mode is memorized by the vehicle. When the 12-volt bat-
tery is reconnected, the system will return to the mode it was in before the
12-volt battery was discharged. Before disconnecting the 12-volt battery,
turn the power switch off.
If you are unsure what mode the power switch was in before the 12-volt bat-
tery discharged, be especially careful when reconnecting the 12-volt battery.

4917-2. Steps to take in an emergency
7
When trouble arises
■When replacing the 12-volt battery
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●Use a 12-volt battery that the case size is same as the previous one (LN2),
20 hour rate capacity (20HR) is equivalent (64Ah) or greater, and perfor-
mance rating (CCA) is equivalent (356A) or greater.
• If the sizes differ, the 12-volt battery cannot be properly secured.
• If the 20 hour rate capacity is low, even if the time period where the vehi-
cle is not used is a short time, the 12-volt battery may discharge and the
hybrid system may not be able to start.
●Use a 12-volt battery with a handle. If a 12-volt battery without a handle is
used, removal is more difficult.
For details, consult your Toyota dealer. ●After replacing, firmly attach the follow-
ing items to the exhaust hole of the 12-
volt battery.
• Use the exhaust hose that was
attached to the 12-volt battery before
replacing and confirm that it is firmly
connected to the hole section of the
vehicle.
• Use the exhaust hole plug included
with the 12-volt battery replaced or
the one installed on the battery prior
to the replacement. (Depending on
the 12-volt battery to be replaced, the
exhaust hole may be plugged.)
Exhaust hole plug
Exhaust hole
Exhaust hose
Hole section of the vehicle
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2
3
4

4937-2. Steps to take in an emergency
7
When trouble arises
WARNING
■When replacing the 12-volt battery
After replacing, securely attach the exhaust hose and exhaust hole plug to
the exhaust hole of the replaced 12-volt battery. If not properly installed,
gases (hydrogen) may leak into the vehicle interior, and there is the possi-
ble danger of the gas igniting and exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entan-
gled in the cooling fan or engine drive belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to be used when charging the 12-volt
battery from another vehicle in an emergency. It cannot be used to jump
start another vehicle.