Page 583 of 681
5838-2. Steps to take in an emergency
8
When trouble arises
NX300h_U_OM78007U Install the wheel nut wrench in jack
handle.
Raise the vehicle until the tire is
slightly raised off the ground.
Remove all the wheel nuts and the
tire. When resting the tire on the ground,
place the tire so that the wheel design
faces up to avoid scratching the wheel
surface.
Remove the wheel ornament by
pushing from the reverse side. 4
5
6
7
Page 586 of 681

586 8-2. Steps to take in an emergency
NX300h_U_OM78007U Lower the vehicle.
Firmly tighten each wheel nut two or
three times in the order shown in the
illustration. Tightening torque:
76 ft•lbf (103 N•m, 10.5 kgf•m)
Vehicles with a full-size spare tire:
Reinstall the wheel ornament.
Stow the flat tire, tire jack and all tools. ■
The compact spare tire (Vehicle with compact spare tire) ●
The compact spare tire is identified by the label “TEMPORARY USE ONLY” on the
tire sidewall.
Use the compact spare tire temporarily, and only in an emergency. ●
Make sure to check the tire inflation pressure of the compact spare tire. ( P. 6 1 5 )■
After completing the tire change
The tire pressure warning system must be reset. ( P. 5 1 8 )■
When using the compact spare tire (Vehicle with compact spare tire)
As the compact spare tire is not equipped wi th a tire pressure warning valve and trans-
mitter, low inflation pressure of the spare ti re will not be indicated by the tire pressure
warning system. Also, if you replace the compact spare tire after the tire pressure warn-
ing light comes on, th e light remains on.■
When the compact spare tire is equippe d (Vehicle with compact spare tire)
The vehicle becomes lower when driving with the compact spare tire compared to when
driving with standard tires. 4
5
6
7
Page 589 of 681

589
8
When trouble arises 8-2. Steps to take in an emergency
NX300h_U_OM78007UIf the hybrid system will not start One of the following may be the cause of the problem: ●
The electronic key may not be functioning properly.
( P. 5 9 2 )●
There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle. ( P. 8 3 )●
There may be a malfunction in the immobilizer system. ( P. 8 6 )●
There may be a malfunction in the steering lock system. ●
The hybrid system may be malfunctioni ng due to an electrical problem such
as electronic key battery depletion or a blown fuse. However, depending on
the type of malfunction, an interim meas ure is available to start the hybrid sys-
tem. ( P. 5 9 0 )
One of the following may be the cause of the problem: ●
The 12-volt battery may be discharged. ( P. 5 9 5 )●
The 12-volt battery terminal connections may be loose or corroded.
( P. 5 1 2 )Reasons for the hybrid system not starting vary depending on the situation.
Check the following and perform the appropriate procedure:
The hybrid system will not start ev en though the correct starting proce-
dure is being followed. ( P. 201)
The interior lights and headlights are dim, or the horn does not sound or
sounds at a low volume.
Page 590 of 681

590 8-2. Steps to take in an emergency
NX300h_U_OM78007U One of the following may be the cause of the problem: ●
The 12-volt battery may be discharged. ( P. 5 9 5 )●
One or both of the 12-volt battery terminals may be disconnected. ( P. 5 1 2 )Contact your Lexus dealer if the problem cannot be repaired, or if repair procedures
are unknown.
When the hybrid system does not start, the following steps can be used as an
interim measure to start the hybrid system if the power switch is functioning nor-
mally:
Do not use this starting procedur e except in cases of emergency.
Set the parking brake.
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for ab out 15 seconds while depressing the
brake pedal firmly.
Even if the hybrid system can be starte d using the above steps, the system may
be malfunctioning. Have the vehicle inspected by your Lexus dealer.The interior lights and headlights do not turn on, or the horn does not
sound.
Emergency start function 1
2
3
4
Page 597 of 681

5978-2. Steps to take in an emergency
8
When trouble arises
NX300h_U_OM78007U Start the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximately 5 minutes to recharge the 12-volt bat-
tery of your vehicle.
Open and close any of the doors of your vehicle with the power switch off.
Maintain the engine speed of the second vehicle and start the hybrid system
of your vehicle by turning the power switch to ON mode.
Make sure the “READY” indicator comes on. If the indicator light does not
come on, contact your Lexus dealer.
Once the hybrid system has started, remove the jumper cables in the exact
reverse order from which they were connected.
Close the exclusive jump starting terminal cover, and reinstall the fuse box
cover to its original position.
Once the hybrid system starts, have th e vehicle inspected at your Lexus dealer
as soon as possible. ■
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. ■
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 appli-
ances. 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 the 12-volt battery is removed or discharged ●
In some cases, it may not be possible to unlock the doors using the smart access system
with push-button start 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 battery 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 battery dis-
charged, be especially careful when reconnecting the 12-volt battery. ●
The power back door must be initialized. ( P. 1 3 4 )●
Make sure that the key is not inside the vehicle when recharging or replacing the
12-volt battery. The key may be locked in the vehicle if the alarm is activated. ( P. 88)5
6
7
8
9
10
Page 598 of 681

598 8-2. Steps to take in an emergency
NX300h_U_OM78007U ■
When exchanging the 12-volt battery ●
Use a Central Degassing type 12-volt battery (European Regulations). Also, use 12-volt
batteries with case si zes similar to one prior the exchange and an equivalent 20 hour
rate capacity (20HR) or greater.
• If the sizes differ, the 12-volt battery can not be properly secured.
• If the 20 hour rate capacity is low, even if the time period where the vehicle is not
used is a short time, the 12-volt battery may discharge and hybrid system may not be
able to start. ●
After exchanging, firmly attach the following items to the exhaust hole of the 12-volt
battery.
For details, consult your Lexus dealer. • Use the exhaust hose that was attached to
the 12-volt battery before exchanging 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 exchanged or the one
installed on the battery prior to the
exchange. (Depending on the 12-volt bat-
tery to be exchanged, the exhaust hole may
be plugged.)
WA R N I N G ■
Avoiding 12-volt battery fires or explosions
Observe the following precautions to preven t accidentally igniting the flammable gas
that may be emitted from the 12-volt battery: ●
Make sure each jumper cable is connected to the correct terminal and that it is not
unintentionally in contact with any other than the intended terminal.●
Do not allow the other end of the jumper cable connected to the “+” terminal to come
into contact with any other parts or metal surfaces in the area, such as brackets or
unpainted metal. ●
Do not allow the + and - clamps of the jump er cables to come in to contact with each
other. ●
Do not smoke, use matches, cigarette lighters or allow open flame near the 12-volt
battery. Exhaust hole
Exhaust
hole plug
Exhaust hoseHole section
of the vehicle
Exhaust hole
Page 613 of 681

6139-1. Specifications
9
Vehicle specifications
NX300h_U_OM78007U * : The coolant capacity is the quantity of reference.
If replacement is necessary, contact your Lexus dealer.Cooling system Capacity
* Gasoline
engine
Vehicles without towing package
7.7 qt. (7.3 L, 6.4 Imp.qt.)
Vehicles with towing package
7.1 qt. (6.7 L, 5.9 Imp.qt.)
Po w e r
control unit 3.3 qt. (3.1 L, 2.7 Imp.qt.)
Coolant type Use either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based
non-silicate, non-amine, non-nitrite, and non-
borate coolant with long-life hybrid organic
acid technology
Do not use plain water alone.
Ignition system (spark plug) Make DENSO FK16HR-A8
Gap 0.03 in. (0.8 mm)
NOTICE ■
Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system 12-volt battery
Open voltage at 68 F (20 C): 12.6 V or higher: Fully charged
12.2 — 12.4 V: Half charged
12.0 V or lower: Discharged
(Voltage is checked 20 minutes after the hybrid
system and all lights are turned off.)
Charging rates 5 A max.
Page 617 of 681
6179-1. Specifications
9
Vehicle specifications
NX300h_U_OM78007U Light bulbs Light bulbs Bulb No. W Ty p e
Exterior Headlights
High beam (halogen bulbs)
* 9005 60 A
Front side marker lights
* W5W 5 C
Front turn signal lights (bulb
type)
* 585
(WY21W) 21 B
Rear turn signal lights 585
(WY21W) 21 B
Back-up lights 921
(W16W) 16 C
Interior Vanity lights 8 C
Luggage compartment light 5 D
A: HB3 halogen bulbs
B: Wedge base bulbs (amber) C: Wedge base bulbs (clear)
D: Double end bulbs
* : If equipped