ECU TOYOTA PRIUS V 2012 (in English) Workshop Manual

442 5-1. Essential information
PRIUS v_U (OM47784U)
CAUTION
■Caution while towing
● Use extreme caution when towing the vehicle.
Avoid sudden starts or erratic driving maneuvers which place excessive
stress on the emergency towing eyelets and the cables or chains. Always
be cautious of the surroundings and other vehicles while towing.
● Do not turn the “POWER” switch off.
This may lead to an accident as the front wheels will be locked by the
parking lock.
● If the hybrid system is off, the power assist for the brakes and steering will
not function, making steering and braking more difficult.
■ Installing towing eyelets to the vehicle
Make sure that towing eyelets are installed securely.
If not securely installed, towing eyelets may come loose during towing. This
may lead to accidents that cause serious injury or even death.
NOTICE
■To prevent damaging the vehicle
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 causing serious damage to the hybrid transmission when
towing using a wheel-lift type truck
Never tow this vehicle from the front with the rear wheels on the ground.
■ To prevent body damage when towing with a sling-type truck
Do not tow with a sling-type truck, either from the front or rear.
■ To prevent causing serious damage to the hybrid transmission in
emergency towing
Never tow a vehicle from the rear with four wheels on the ground. This may
cause serious damage to the hybrid transmission.

5
When trouble arises
447
5-2. Steps to take in an emergency
PRIUS v_U (OM47784U)
Warning lightWarning light/Details
(Flashes)
(If equipped) Pre-collision syst
em warning light
Indicates a malfunction in the pre-collision system
The warning light will operate as follows, even when the
system is not malfunctioning:
• The light will flash quickly when the system is operating. (P. 258)
• The light will turn on when the pre-collision braking is disabled. ( P. 259)
• The light will turn on when the system cannot tempo- rarily be used. ( P. 450)
(Turns on) Slip indicator light
Indicates a malfunction in:
•VSC;
• TRAC; or
• Hill-start assist control
Flashes when the above systems are operating.
(P. 253)
Brake system warning light (yellow indicator)
Indicates a malfunction in:
• The regenerative braking system; or
• The electronically controlled brake system
Parking lock system warnin
g light (warning buzzer)
Indicates a malfunction in the P position control system
• In this situation, there is a possibility that the parking lock mechanism will not work. When parking, park the
vehicle on a flat surface and apply the parking brake
securely.
• The “POWER” switch may not be turned off. If this hap- pens, applying the parking brake will enable the switch
to be turned off.

448 5-2. Steps to take in an emergency
PRIUS v_U (OM47784U)
Warning lightWarning light/Details

(U.S.A)

(Canada) Parking lock system warn
ing message (warning
buzzer) Indicates a malfunction in the P position control system
when the vehicle is stopped
• In this situation, there is a possibility that the parking lock mechanism will not work. When parking, park the
vehicle on a flat surface and apply the parking brake
securely.
• The “POWER” switch may not be turned off. If this hap- pens, applying the parking brake will enable the switch
to be turned off.

(If equipped) LED headlight warning light
Indicates a malfunction in the LED headlightsThe LED headlights will not normally illuminate when
there is a malfunction, however it may be able to illumi-
nate depending on the nature of the problem.

(If equipped) Automatic headlight leveling system warning light
Indicates a malfunction in the automatic headlight level-
ing system

(If equipped) (yellow) Cruise control indicator
Indicates a malfunction in the cruise control/dynamic
radar cruise control

(If equipped) (yellow) Radar cruise control indicator
Indicates a malfunction in the dynamic radar cruise con-
trol

452 5-2. Steps to take in an emergency
PRIUS v_U (OM47784U)
*1: Refer to the separate “Scheduled Maintenance Guide” or “Owner’s ManualSupplement” for the maintenance interval applicable to your vehicle.
*2: Open door warning buzzer:
The open door warning buzzer sounds to alert one or more of the doors is
not fully closed (with the vehicle having reached a speed of 3 mph [5km/h]).
*3: Seat belt warning buzzer:The seat belt warning buzzer sounds to alert the driver and/or front passen-
ger that their seat belts are not fastened. If the driver’s seat belt is not fas-
tened, the buzzer will sound for 6 seconds once the “POWER” switch is
turned to ON mode. If the vehicle reaches a speed of 12 mph (20 km/h), the
buzzer will sound once. If the seat belt is still unfastened after 30 seconds,
the buzzer will sound intermittently for 10 seconds. Then, if the seat belt is
still unfastened, the buzzer will sound in a different tone for 20 more sec-
onds.
■ 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 BA G OFF” indicator light, front passen-
ger’s seat belt buckle switch, seat belt pretensioner assemblies, airbags,
interconnecting wiring and power sources. ( P. 124)
■ Front passenger occupant classifi cation system (ECU and sensors),
seat belt reminder and warning buzzer
● If luggage is placed on the front passenger seat, the front passenger
occupant classification system (ECU and sensors) may cause the warn-
ing 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 front passenger occupant classifi-
cation system (ECU and sensors) may not detect a passenger, and the
warning light may not operate properly.

5
When trouble arises
453
5-2. Steps to take in an emergency
PRIUS v_U (OM47784U)
■
Electric power steering system warning light
When the 12-volt battery charge becomes insufficient or the voltage tempo-
rarily drops, the electric power steering system warning light may come on.
■ 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 malfunction indicator lamp will go off after several driving trips.
If the malfunction indicator lamp does not go off even after several trips, con-
tact your Toyota dealer as soon as possible.
■
When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level.
Pushing the tire pressure warning re set switch will not turn off the tire
pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such
as natural air leaks and tire inflat ion pressure changes caused by tem-
perature. In this case, adjusting the tire inflation pressure will turn off the
warning light (after a few minutes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with a tire pressure warning
valve and transmitter. If a tire goes flat, the tire pressure warning light will
not turn off even though the flat tire has been replaced with the spare
tire. Replace the spare tire with the re paired tire and adjust the tire infla-
tion pressure. The tire pressure wa rning light will go off after a few min-
utes.

464 5-2. Steps to take in an emergency
PRIUS v_U (OM47784U)
Taking out the spare tireUnload the tool holder from the
vehicle and loosen the center
fastener that secures the spare
tire.
CAUTION
■Service plug
Be careful not to hit the service plug when loading or unloading the tool
holder or the spare tire. (P. 3 9 )

5
When trouble arises
471
5-2. Steps to take in an emergency
PRIUS v_U (OM47784U)
Pass the belt through the buckle
and secure the tire firmly. Check
that the belt is securely held by
the buckle.
The belt cannot be fastened
securely if the buckle is facing
the wrong direction.
STEP 4
■The compact spare tire
●The compact spare tire is identifi
ed 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. 504)
■After completing the tire change
The tire pressure warning system must be reset. (P. 391)
■When using the compact spare tire
As the compact spare tire is not equipped with a tire pressure warning
valve and transmitter, low inflation pressure of the spare tire will not be
indicated by the tire pressure warning system. Also, if you replace the
compact spare tire after the tire pressure warning light comes on, the
light remains on.
■If you have a flat front tire on a road covered with snow or ice
Install the compact spare tire on one of the rear wheels of the vehicle.
Perform the following steps and fit tire chains to the front tires:
Replace a rear tire with the compact spare tire.
Replace the flat front tire with the tire removed from the rear of
the vehicle.
Fit tire chains to the front tires.
STEP 1
STEP 2
STEP 3

5
When trouble arises
473
5-2. Steps to take in an emergency
PRIUS v_U (OM47784U)
CAUTION
■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. Failure
to observe this precaution may lead to
an accident causing death or seri-
ous injury.
■Using the tire jack
Improper use of the tire jack may cause the vehicle to suddenly fall off
the jack, leading to death or serious injury.
Observe the following precautions:
●Do not use the tire jack for any pu rpose other than replacing tires or
installing and removing tire chains.
●Only use the tire jack that comes wi th this vehicle for replacing a flat
tire.
Do not use it on other vehicles, and do not use other tire jacks for
replacing tires on this vehicle.
●Always check that the tire jack is securely set to the jack point.
●Do not put any part of your body under the vehicle while it is supported
by the jack.
●Do not start or run the hybrid system while your vehicle is supported by
the jack.
●Do not raise the vehicle while someone is inside.
●When raising the vehicle, do not put an object on or under the jack.
●Do not raise the vehicle to a hei ght greater than that required to
replace the tire.
●Use a jack stand if it is necessary to get under the vehicle.
Take particular care when lowering the vehicle to ensure that no one
working on or near the vehicle may be injured.

474 5-2. Steps to take in an emergency
PRIUS v_U (OM47784U)
CAUTION
■Replacing a flat tire
●Do not touch the disc wheels or the area around the brakes immedi-
ately after the vehicle has been driven.
After the vehicle has been driven the disc wheels and the area around
the brakes will be extremely hot. Touching these areas with hands, feet
or other body parts while changing a tire, etc. may result in burns.
●Failure to follow these precautions could cause the wheel nuts to
loosen and the tire to fall off, resulting in death or serious injury.
• Have the wheel nuts tightened with a torque wrench to 76 ft•lbf (103 N•m, 10.5 kgf•m) as soon as possible after changing wheels.
• When installing a tire, only use wheel nuts that have been specifi- cally designed for that wheel.
• If there are any cracks or deformations in the bolt screws, nut threads or bolt holes of the wheel, have the vehicle inspected by
your Toyota dealer.
• When installing the wheel nuts, be sure to install the wheel nuts
with the tapered end facing inward. ( P. 403)
■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 po ssibility of personal injury during a
collision or sudden braking.
■When stowing the flat tire
●Make sure the rear seatbacks are in their original position.
●Secure it using a tire tie-down belt. Otherwise, the flat tire may fly out
in case of sudden braking or an a ccident, resulting in death or serious
injury.

5
When trouble arises
493
5-2. Steps to take in an emergency
PRIUS v_U (OM47784U)
If your vehicle has to be stopped in an emergency
Only in an emergency, such as if it becomes impossible to stop the
vehicle in the normal way, stop the vehicle using the following pro-
cedure:
Steadily step on the brake pedal with both feet and firmly
depress it.
Do not pump the brake pedal repeatedly as this will increase the
effort required to slow the vehicle.
Shift the shift position to N.
If the shift position is shifted to N After slowing down, stop the vehi cle in a safe place by the
road.
Stop the hybrid system.
If the shift position cannot be shifted to N Keep depressing the brake pedal with both feet to reduce
vehicle speed as much as possible.
To stop the hybrid system,
press and hold the “POWER”
switch for 3 consecutive sec-
onds or more, or press it
briefly for 3 times or more in
succession.
Stop the vehicle in a safe place by the road.
STEP 1
STEP 2
STEP 3
STEP 4
STEP 3
STEP 4
Press and hold for 3 seconds or more, or press briefly for 3 times or more
STEP 5