2023 TOYOTA SIENNA HYBRID engine

5057-2. Steps to take in an emergency
7
When trouble arises
up the cover.3Open the exclusive jump
starting terminal cover.
4 Connect a positive jumper cable clamp to on your vehicle and
connect the clamp on the other end of the positive cable to on
the second vehicle. Then, connect a negative cable clamp to
on the second vehicle and connect the clamp at the other end of
the negative cable to .
Exclusive jump starting terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery term inal (second vehicle)
Solid, stationary, unpainted metallic point away from the exclu -
sive jump starting terminal and any moving parts as shown in th e
illustration
5 Start the engine of the sec-
ond vehicle. Increase the
engine speed slightly and maintain at that level for
approximately 5 minutes to
A
B
C
D
A
B
C
D

5067-2. Steps to take in an emergency
recharge the 12-volt battery
of your vehicle.
6 Maintain the engine speed of
the second vehicle and start
the hybrid system of your
vehicle by turning the power
switch to ON.
7 Make sure the “READY” indi-
cator comes on. If the indica-
tor light does not come on,
contact your Toyota dealer.
8 Once the hybrid system has
started, remove the jumper
cables in the exact reverse
order from which they were
connected.
9 Close the exclusive jump
starting terminal cover, and
reinstall the fuse box cover to
its original position.
Once the hybrid system starts,
have the vehicle inspected at
your Toyota dealer as soon as
possible.
■Starting the hybrid system
when the 12-volt battery is dis-
charged
The hybrid system cannot be
started by push-starting.
■To prevent 12-vol t battery dis-
charge
●Turn off the headlights and the
audio system while the hybrid sys-
tem is off.
●Turn off any unnec essary electri-
cal 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 you r Toyota dealer.
●Some systems may require initial-
ization. (P.551)
■When removing the 12-volt bat-
tery terminals
When the 12-volt battery terminals
are removed, the information stored
in the ECU is cleared. Before
removing the 12- volt battery termi-
nals, contact your Toyota dealer.
■Charging the 12-volt battery
The electricity stored in the 12-volt
battery will discha rge gradually even
when the vehicle i s not in use, due
to natural dischar ge and the drain-
ing effects of certain electrical appli-
ances. If the vehicle is left for a long
time, the 12-volt battery may dis-
charge, and the hybrid system may
be unable to start. (The 12-volt bat-
tery recharges automatically while
the hybrid system is operating.)
■When recharging or replacing
the 12-volt battery
●In some cases, it may not be pos-
sible to unlock the doors using the
smart key system when the 12-
volt battery is discharged. Use the
wireless remote c ontrol or the
mechanical key to lock or unlock
the doors.
●The hybrid syste m may not start
on the first attemp t after reinstall-
ing the 12-volt battery. In that
case, start the hybrid system in
the same manner as when the
electronic key does not operate
properly ( P.503). This is not a
malfunction, as the hybrid system
will start normally on the second
attempt.
●The power switch mode is memo-
rized by the vehicle. When the 12-
volt battery is reconnected, the
system will return to the mode it

5097-2. Steps to take in an emergency
7
When trouble arises
■If the engine coolant tem-
perature gauge enters the
red zone or “Engine Cool-
ant Temp High Stop in a
Safe Place See Owner’s
Manual” is shown on the
multi-information display
1 Stop the vehicle in a safe
place and turn off the air con-
ditioning system, and then
stop the hybrid system. 2
If you see steam:
Carefully lift the hood after
the steam subsides.
If you do not see steam:
Carefully lift the hood.
3 After the hybrid system has
cooled down sufficiently,
inspect the hoses and radia-
tor core (radiator) for any
leaks.
Radiator
Cooling fan
If a large amount of coolant leaks,
immediately contact your Toyota
dealer.
4The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL” line
If your vehicle over-
heats
The following may indicate
that your vehicle is over-
heating.
The needle of the engine
coolant temperature gauge
( P.97, 101) enters the red
zone, or a loss of hybrid
system power is experi-
enced. (For example, the
vehicle speed does not
increase.)
 “Engine Coolant Temp High
Stop in a Safe Place See
Owner’s Manual” or “Hybrid
System Overheated Output
Power Reduced” is shown
on the multi-information dis-
play.
Steam comes out from
under the hood.
Correction procedures
A
B
A
B

5107-2. Steps to take in an emergency
“LOW” line
5 Add coolant if necessary.
Water can be us ed in an emer-
gency if engine coolant is unavail-
able.
6 Start the hybrid system and
turn the air conditioning sys-
tem on to check that the radi-
ator cooling fan operates and
to check for coolant leaks
from the radiator or hoses.
The fan operates when the air con-
ditioning system is turned on imme-
diately after a cold start. Confirm
that the fan is op erating by check-
ing the fan sound and air flow. If it is
difficult to check th ese, turn the air
conditioning system on and off
repeatedly. (The f an may not oper-
ate in freezing temperatures.)
7 If the fan is not operating:
Stop the hybrid system
immediately and contact your
Toyota dealer.
If the fan is operating:
Have the vehicle inspected at
the nearest Toyota dealer.
8 Check if “Engine Coolant
Temp High Stop in a Safe
Place See Owner’s Manual”
is shown on the multi-infor-
mation display.
If the message does not disappear:
Stop the hybrid system and contact
your Toyota dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Toyota dealer.
■If “Hybrid System Over-
heated Output Power
Reduced” is shown on the
multi-information display
1 Stop the vehicle in a safe
place.
2 Stop the hybrid system and
carefully lift the hood.
3 After the hybrid system has
cooled down, inspect the
hoses and radiator core (radi-
ator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant leaks,
immediately contact your Toyota
dealer.
4The coolant level is satisfac-
tory if it is between the
C
A
B

5117-2. Steps to take in an emergency
7
When trouble arises
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL” line
“LOW” line
5 Add coolant if necessary.
Water can be used in an emer-
gency if power control unit coolant
is unavailable.
6After stopping the hybrid sys-
tem and waiting for 5 minutes
or more, start the hybrid sys-
tem again and check for the
multi-information display.
If the message does not disappear:
Stop the hybrid system and contact
your Toyota dealer.
If the message is not displayed:
The hybrid system temperature has
dropped and the vehicle may be
driven normally.
However, if the message appears
again frequently, contact your Toyota dealer.
A
B
C
WARNING
■When inspecting under the
hood of your vehicle
Observe the following precau-
tions.
Failure to do so may result in seri-
ous injury such as burns.
●If steam is seen coming from
under the hood, do not open the
hood until the steam has sub-
sided. The engine compart-
ment may be very hot.
●After the hybrid system has
been turned off , check that the
“READY” indicator is off.
When the hybrid system is oper-
ating, the gasoline engine may
automatically start, or the cool-
ing fan may suddenly operate
even if the gasoline engine
stops. Do not touch or approach
rotating parts such as the fan,
which may lead to fingers or
clothing (especially a tie, a scarf
or a muffler) getting caught,
resulting in serious injury.
●Do not loosen the coolant reser-
voir cap while the hybrid system
and radiator are hot.
High temperature steam or
coolant could spray out.
NOTICE
■When adding engine/power
control unit coolant
Add coolant slowly after the
hybrid system has cooled down
sufficiently. Adding cool coolant to
a hot hybrid system too quickly
can cause damage to the hybrid
system.

5188-1. Specifications
■Engine number
The engine number is stamped on the engine block as shown.
Front
Engine
Model2.5 L 4-cylinder (A25A-FXS)
Type4-cylinder in line
, 4-cycle, gasoline
Bore and stroke3.44  4.07 in. (87.5  103.4 mm)
Displacement151.8 cu. in. (2487 cm3)
Valve clearanceAutomatic adjustment
Fuel
Fuel typeUnleaded gasoline only
Octane Rating87 (Research Octane Number 91) or
higher
Fuel tank capacity (Reference)18 gal. (68.2 L, 15 Imp.gal.)
Electric motor (traction motor)
TypePermanent magnet synchronous motor
Maximum output134 kW
Maximum torque199 ft•lbf (270 N•m, 27.5 kgf•m)

5198-1. Specifications
8
Vehicle specifications
Rear (AWD models)
■Oil capacity (Drain and refill
 reference
*)
*: The engine oil capacity is a refer-
ence quantity to be used when
changing the engine oil. Warm up
the engine and turn off the hybrid
system, wait more than 5 min-
utes, and check the oil level on
the dipstick.
■Engine oil selection
“Toyota Genuine Motor Oil” is
used in your Toyota vehicle.
Use Toyota approved “Toyota
Genuine Motor Oil” or equiva-
lent to satisfy the following
grade and viscosity.
Oil grade: ILSAC GF-6B multigrade engine
oil
Recommended viscosity:
SAE 0W-16
SAE 0W-16 is the best choice
for good fuel economy and good
starting in cold weather.
If SAE 0W-16 is not available,
SAE 0W-20 oil may be used.
However, it must be replaced
with SAE 0W-16 at the next oil
change.
TypePermanent magnet synchronous motor
Maximum output40 kW
Maximum torque89.2 ft•lbf (121 N•m, 12.3 kgf•m)
Hybrid battery (traction battery)
TypeNickel-Metal hy
dride battery
Voltage7.2 V/module
Capacity6.5 Ah (3HR)
Quantity40 modules
Nominal voltage288 V
Lubrication system
With filter4.8 qt. (4.5 L, 4.0 Imp.
qt.)
Without fil-
ter4.4 qt. (4.2 L, 3.7 Imp.
qt.)

5208-1. Specifications
Outside temperature
Oil viscosity (0W-16 is explained
here as an example):
• The 0W in 0W-16 indicates the characteristic of the oil
which allows cold startability.
Oils with a lower value before
the W allow for easier starting
of the engine in cold weather.
• The 16 in 0W-16 indicates the viscosity characteristic of the
oil when the oil is at high tem-
perature. An oil with a higher
viscosity (one with a higher
value) may be better suited if the vehicle is operated at high
speeds, or under extreme
load conditions.
How to read oil container label:
API registered mark is added to
some oil containers to help you
select the oil you should use.
*: The coolant capacity is the quantity of reference.
If replacement is ne cessary, contact your Toyota dealer.
A
Cooling system
Capacity*Gasoline engine11.4 qt. (10.8 L, 9.5 Imp. qt.)
Power control unit2.0 qt. (1.9 L, 1.7 Imp. qt.)
Coolant type
Use either of the following:
“Toyota Super Long Life Coolant”
 Similar high-quality ethylene gly-
col-based non-silicate, non-amine,
non-nitrite, and non-borate cool-
ant with long-life hybrid organic
acid technology
Do not use plain water alone.
Ignition system (spark plug)
MakeDENSO FC16HR-Q8
Gap0.031 in. (0.8 mm)