3087-2. Steps to take in an emergency
changed each time the switch is pressed. 
( P.127)
If you have a set of jumper (or booster) 
cables and a second vehicle with a 
12-volt battery, you can jump start your 
vehicle by following the steps below.
1 Confirm that the electronic key is 
being carried.
When connecting the jumper (or booster) 
cables, depending on the situation, the 
alarm may activate and doors locked. 
( P.58)
2 Open the hood. ( P.247)
If the vehicle battery is dis-
charged
The following procedures may be 
used to start the engine if the vehi-
cle’s battery is discharged.
You can also call your Lexus dealer 
or a qualified repair shop.
Restarting the engine 
3097-2. Steps to take in an emergency
7
When trouble arises
3Connect a positive jumper cable clamp to   on your vehicle and connect the 
clamp on the other end of the positive cab le 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  .
 RC350/RC300 AWD
Positive (+) battery terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic poin t away from the battery and any mov-
ing parts as shown in the illustration
 RC300
Positive (+) battery terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic poin t away from the battery and any mov-
ing parts as shown in the illustration
4 Start the engine of the second vehi-
cle. Increase the engine speed 
slightly and maintain at that level for 
approximately 5 minutes to  recharge the battery of your vehi-
cle.A
B
C
D
A
B
C
D
A
B
C
D 
3107-2. Steps to take in an emergency
5Open and close any of the door of 
your vehicle with the engine switch 
off.
6
Maintain the engine speed of the 
second vehicle and start the engine 
of your vehicle by turning the 
engine switch to IGNITION ON 
mode.
7
Once the vehicle’s engine has 
started, remove the jumper cables 
in the exact reverse order from 
which they were connected.
Once the engine starts, have the vehi-
cle inspected at your Lexus dealer as 
soon as possible.
■Starting the engine when the battery is 
discharged
The engine cannot be started by push-start-
ing.
■To prevent battery discharge
●Turn off the headlights and the audio sys-
tem while the engine is off.
●Turn off any unnecessary electrical com-
ponents when the vehicle is running at a 
low speed for an extended period, such 
as in heavy traffic.
■Charging the battery
The electricity stored in the battery will dis-
charge 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 battery may discharge, and the engine 
may be unable to start. (The battery 
recharges automatically during driving.)
■When recharging or replacing the bat-
tery
●In some cases, it may not be possible to 
unlock the doors using the smart access 
system with push-button start when the 
battery is discharged. Use the wireless 
remote control or the mechanical key to 
lock or unlock the doors.
●The engine may not start on the first 
attempt after the battery has recharged 
but will start normally after the second 
attempt. This is not a malfunction.
●The engine switch mode is memorized by 
the vehicle. When the battery is recon-
nected, the system will return to the 
mode it was in before the battery was dis-
charged. Before disconnecting the bat-
tery, turn the engine switch off.
If you are unsure wh at mode the engine 
switch was in before the battery dis-
charged, be especially careful when 
reconnecting the battery.
WARNING
■Avoiding battery fires or explosions
Observe the following precautions to 
prevent accidentally igniting the flamma-
ble gas that may be emitted from the bat-
tery:
●Make sure each jumper cable is con-
nected to the correct terminal and that 
it is not unintentiona lly in contact with 
any other than the intended terminal.
●Do not allow the other end of the 
jumper cable connected to the “+” ter-
minal 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 
jumper cables to come into contact 
with each other.
●Do not smoke, use matches, cigarette 
lighters or allow open flame near the 
battery.
■Battery precautions
The battery contains poisonous and cor-
rosive acidic electrol yte, while related 
parts contain lead and lead compounds. 
Observe the following precautions when 
handling the battery: