2015 LEXUS NX300h coolant temperature

564 8-2. Steps to take in an emergency
NX300h_U_OM78007UIf you think something is wrong ●
Fluid leaks under the vehicle
(Water dripping from the air co nditioning after use is normal.)●
Flat-looking tires or uneven tire wear ●
Engine coolant temperature gauge needle continually points higher than nor-
mal ●
Changes in exhaust sound ●
Excessive tire squeal when cornering ●
Strange noises related to the suspension system ●
Pinging or other noises related to the hybrid system ●
Engine misfire or misses, st umbling or running roughly●
Appreciable loss of power ●
Vehicle pulls heavily to one side when braking ●
Vehicle pulls heavily to one side when driving on a level road ●
Loss of brake effectiveness, spongy f eeling, pedal almost touches the floorIf you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

565
8
When trouble arises 8-2. Steps to take in an emergency
NX300h_U_OM78007UIf a warning light turns on or a warning buzzer
sounds Calmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, bu t then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspected by your Lexus dealer.
Warning light and warning buzzer list Warning light Warning light/Details/Actions(U.S.A.)
(Canada)
Brake system warning light
Indicates that:
• The brake fluid level is low; or
• The brake system is malfunctioning
 Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
* 1
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
 Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
* 1
Low engine oil pressure warning light (warning buzzer)
Indicates that the engine oil pressure is too low
 Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
* 1
High coolant temperature warning light (warning buzzer)
Indicates that the engine is overheating
 Immediately stop the vehicle in a safe place. Continuing to drive
the vehicle may be dangerous.
Handling method (  P. 600)
Brake system warning light
Indicates a malfunction in:
• The regenerative braking system;
• The electronically controlled brake system; or
• The electric parking brake
 Have the vehicle inspected by your Lexus dealer immediately. (U.S.A.)
(Canada)
Malfunction indicator lamp
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The emission control system
 Have the vehicle inspected by your Lexus dealer immediately.

600 8-2. Steps to take in an emergency
NX300h_U_OM78007UIf your vehicle overheats ■
“Engine Coolant Temp High” is shown on the multi-information display
Stop the vehicle in a safe place and tu rn off the air conditioning system, and
then stop the hybrid system.
If you see steam: Carefully lift the hood after the steam subsides.
If you do not see steam: Carefully lift the hood.
After the hybrid system has cooled down sufficiently, inspect the hoses and
radiator core (radiator) for any leaks.
Radiator
Cooling fans If a large amount of coolant leaks,
immediately contact your Lexus
dealer.The following may indicate that your vehicle is overheating. ●
The needle of the engine coolant temperature gauge (  P. 97) enters the
red zone, or a loss of hybrid system po wer is experienced. (For example, the
vehicle speed does not increase.) ●
“Engine Coolant Temp High” or “Hybrid System Overheated” is shown on
the multi-information display. ●
Steam comes out from under the hood.
Correction procedures 1
2
3
1
2

6018-2. Steps to take in an emergency
8
When trouble arises
NX300h_U_OM78007U The coolant level is satisfactory if it is between the “FULL” and “LOW” lines
on the reservoir.
Reservoir
“FULL” line
“LOW” line
Add coolant if necessary. Water can be used in an emergency
if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to check
that the radiator cooling fans operate and to check for coolant leaks from
the radiator or hoses. The fans operate when the air conditioning system is turned on immediately after a
cold start. Confirm that the fans are op erating by checking the fan sound and air
flow. If it is difficult to check these, tu rn the air conditioning system on and off
repeatedly. (The fans may not operate in freezing temperatures.)
If the fans are not operating: Stop the hybrid system immediately and contact your Lexus dealer.
If the fans are operating: Have the vehicle inspected at the nearest Lexus dealer.
Check if “Engine Coolant Temp High” is shown on the multi-information
display.
If the message does not disappear:
Stop the hybrid system and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer. 4
1
2
3
5
6
7
8

6038-2. Steps to take in an emergency
8
When trouble arises
NX300h_U_OM78007U Start the hybrid system and check if “Hybrid System Overheated” is shown
on the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer. WA R N I N G ■
To prevent an accident or injury when in specting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns. ●
If steam is seen coming from under the h ood, do not open the hood until the steam
has subsided. The engine compartment may be very hot. ●
After the hybrid system has been turned off, check that the “READY” indicator are
off.
When the hybrid system is operating, the gasoline engine may au tomatically start, or
the cooling fan may suddenly operate even if the gasoline engine stops. Do not touch
or approach rotating parts such as the fa n, which may lead to fingers or clothing
(especially a tie, a scarf or a muffler) ge tting caught, resulting in serious injury.●
Do not loosen the coolant reservoir 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. ■
To prevent damage to the cooling system
Observe the following precautions: ●
Avoid contaminating the coolant with foreign matter (such as sand or dust etc.). ●
Do not use any coolant additive. 6

667Alphabetical index
NX300h_U_OM78007U If you have a flat tire ..........................575
If you lose your keys ................ 120, 122
If you think something is
wrong .................................................. 564
If your vehicle becomes
stuck ..................................................... 604
If your vehicle has to
be stopped in an
emergency.........................................557
If your vehicle needs to be
towed................................................... 558
If your vehicle overheats ............... 600
Energy monitor ..........................................111
Engine
Accessory mode................................202
Compartment..................................... 502
Engine switch ........................................ 201
Hood ....................................................... 500
How to start the hybrid
system ................................................... 201
Identification number ........................ 610
If your vehicle has to be
stopped in an emergency ..........557
Ignition switch
(power switch).................................. 201
Overheating ........................................ 600
Power switch......................................... 201 Engine compartment cover............. 503
Engine coolant
Capacity...................................................613
Checking .............................................. 508
Preparing and checking
before winter .................................... 326
Warning light .......................................565
Engine coolant temperature
gauge ......................................................... 97
Engine oil
Capacity.................................................... 611
Checking ...............................................504
Warning light .......................................565
Engine oil maintenance data ........... 506
Engine switch ........................................... 201
EPS (Electronic Power Steering)
Function ..................................................305
Warning light .......................................566
EV indicator ............................................... 79
EV drive mode ...................................... 206
Event data recorder (EDR).....................11

672 Alphabetical index
NX300h_U_OM78007U Multi-information display
Drive information ................................ 103
Dynamic radar cruise
control ..................................................240
Dynamic radar cruise control
with full-speed range ....................253
Energy monitor ........................................ 111
Language .............................................. 638
LDA (Lane Departure Alert
with steering control) ...................253
Warning messages........................... 572
Navigation system
*Noise from under vehicle ....................... 8
Odometer ...................................................97
Oil
Engine oil................................................... 611
Rear differential oil .............................. 614
Opener
Back door ............................................... 130
Fuel filler door ......................................236
Hood ....................................................... 500
Outside rear view mirrors ..................163
Adjusting and folding........................ 163
Blind Spot Monitor (BSM)............. 316
Linked mirror function
when reversing ................................. 164
Mirror position memory .................. 154
Outside rear view mirror
defoggers ...........................................435 Outside temperature display .............. 97
Overheating........................................... 600
Panic mode ................................................ 119
Parking brake
Operation................................................ 213
Parking brake engaged
warning buzzer/message ........... 215
Warning light .......................................566
Parking lights
Light switch............................................. 219
Replacing light bulbs ....................... 552
Warning light .......................................566
PCS (Pre-Collision System)
Function ................................................... 310
PCS switch ...............................................311
Warning light .......................................566
Warning message............................. 572
Personal lights ........................................443
Switch ...................................................... 444
Power back door opener and
closer ....................................................... 129
Power control unit coolant
Capacity...................................................613
Checking .............................................. 508
Preparing and checking
before winter .................................... 326
Radiator ................................................. 509N
O P

678 Alphabetical index
NX300h_U_OM78007U Warning buzzers
Approach warning ............... 245, 259
Downshifting ......................................... 210
Intuitive parking assist ......................282
Light reminder ....................................... 221
Open door ............................................. 128
Seat belt reminder .............................567
Warning lights
ABS.......................................................... 566
Brake hold operated
indicator ............................................. 566
Brake Override System .................567
Brake system....................................... 565
Charging system............................... 565
Drive-Start Control...........................567
Electric power st eering.................. 566
High coolant temperature............ 565
Low engine oil pressure ................ 565
Low fuel level .......................................567
Malfunction indicator lamp .......... 565
Master warning light.........................567
Parking brake indicator ................. 566
PCS warning light ............................ 566
Seat belt reminder light...................567
Slip indicator ........................................ 566
SRS ........................................................... 566
Tire pressure ........................................567 Warning messages...............................572
Washer
Checking .................................................. 511
Low washer fluid
warning message.................. 511, 572
Preparing and checking
before winter .................................... 326
Switch ...................................................... 228
Washing and waxing .......................... 484
Weights
Cargo capacity........................182, 608
Load limits ................................. 186, 608
Weights ................................................. 608
Wheels ..................................................... 528
Replacing wheels ..............................528
Size .............................................................615
Window glasses...................................... 166
Window lock switch.............................. 166
Windows
Power windows....................................166
Rear window defogger .................. 435
Washer ................................................... 228
Windshield wiper de-icer ................. 436
Windshield wipers
Intermittent windshield wipers .... 228
Rain-sensing windshield
wipers................................................... 230
Winter driving tips ................................326
Wireless charger.................................. 458W