PRE-COLLISION: PRE-COLLISION SYSTEM (for HV Model): PRECAUTION; 2020 - 2022 MY Corolla Corolla HV [01/2019

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM100000001G4DM
Model Year Start: 2020	Model: Corolla	Prod Date Range: [01/2019 - 09/2022]
Title: PRE-COLLISION: PRE-COLLISION SYSTEM (for HV Model): PRECAUTION; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

PRECAUTION

PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE AUXILIARY BATTERY TERMINAL

NOTICE:

When disconnecting the cable from the negative (-) auxiliary battery terminal, initialize the following systems after the cable is reconnected.

System Name	See Procedure
Lane Control System
Pre-collision System

If the auxiliary battery has been discharged and charged or the cable has been disconnected and reconnected to the negative (-) auxiliary battery terminal, perform Steering Sensor Zero Point Calibration.
Click here

PRE-COLLISION SYSTEM OPERATION CONDITIONS

CAUTION:

When driving on public roads, obey all speed limits and traffic laws.

(a) The pre-collision system is enabled and the system determines that the possibility of a frontal collision with a detected object is high. Each function is operational at the following speed

Pre-collision warning:

Operation target	Vehicle speed	Relative speed between your vehicle and object
Vehicles	Approximately 10 to 180 km/h (7 to 110 mph)	Approximately 10 to 180 km/h (7 to 110 mph)
Bicyclists and pedestrians*	Approximately 10 to 80 km/h (7 to 50 mph)	Approximately 10 to 80 km/h (7 to 50 mph)

Pre-collision brake assist:

Operation target	Vehicle speed	Relative speed between your vehicle and object
Vehicles	Approximately 30 to 180 km/h (20 to 110 mph)	Approximately 30 to 180 km/h (20 to 110 mph)
Bicyclists and pedestrians*	Approximately 30 to 80 km/h (20 to 50 mph)	Approximately 30 to 80 km/h (20 to 50 mph)

Pre-collision braking:

Operation target	Vehicle speed	Relative speed between your vehicle and object
Vehicles	Approximately 10 to 180 km/h (7 to 110 mph)	Approximately 10 to 180 km/h (7 to 110 mph)
Bicyclists and pedestrians*	Approximately 10 to 80 km/h (7 to 50 mph)	Approximately 10 to 80 km/h (7 to 50 mph)

*: Applicable to vehicles designed for regions that detection of pedestrians and/or bicyclists is possible.

(b) Cancelation of the pre-collision braking

(1) If either of the following occur while the pre-collision braking function is operating, it will be canceled:

The accelerator pedal is depressed strongly
The steering wheel is turned sharply or abruptly

During the time until steering sensor zero point calibration is complete
When the shift position is in R
When VSC is off (Collision warning will still operate)
When the PCS warning light is illuminated

PRECAUTIONS FOR PRE-COLLISION SYSTEM

(a) Conditions under which the system may operate even if there is no possibility of a collision.

In some situations such as the following, the system may determine that there is a possibility of a frontal collision and operate.

When passing a detectable object, etc.
When changing lanes while overtaking a detectable object, etc.
When approaching a detectable object in an adjacent lane or on the roadside, such as when changing the course of travel or driving on a winding road
When rapidly closing on a detectable object, etc.
When approaching objects on the roadside, such as detectable objects, guardrails, utility poles, trees, or walls
When there is a detectable object or other object by the roadside at the entrance of a curve
When there are patterns or paint in front of your vehicle that may be mistaken for a detectable object
When the front of your vehicle is hit by water, snow, dust, etc.
When overtaking a detectable object that is changing lanes or making a right/left turn
When passing a detectable object in an oncoming lane that is stopped to make a right/left turn
When a detectable object approaches very close and then stops before entering the path of the vehicle
If the front of your vehicle is raised or lowered, such as when on an uneven or undulating road surface
When driving on a road surrounded by a structure, such as in a tunnel or on a steel bridge
When there is a metal object (manhole cover, steel plate, etc.), steps, or a protrusion in front of your vehicle
When passing under an object (road sign, billboard, etc.)
When approaching an electric toll gate barrier, parking area barrier, or other barrier that opens and closes
When using an automatic car wash
When driving through or under objects that may contact the vehicle, such as thick grass, tree branches, or a banner
When driving through steam or smoke
When driving near an object that reflects radio waves, such as a large truck or guardrail
When driving near a TV tower, broadcasting station, electric power plant, or other location where strong radio waves or electrical noise may be present

(b) Situations in which the system may not operate properly

In some situations such as the following, an object may not be detected by the millimeter wave radar sensor assembly and forward recognition camera, preventing the system from operating properly:

When a detectable object is approaching your vehicle
When your vehicle or a detectable object is wobbling
If a detectable object makes an abrupt maneuver (such as sudden swerving, acceleration or deceleration)
When your vehicle approaches a detectable object rapidly
When a detectable object is not directly in front of your vehicle
When a detectable object is near a wall, fence, guardrail, manhole cover, vehicle, steel plate on the road, etc.
When a detectable object is under a structure
When part of a detectable object is hidden by an object, such as large baggage, an umbrella, or guardrail
When multiple detectable objects are close together
If the sun or other light is shining directly on a detectable object
When a detectable object is a shade of white and looks extremely bright
When a detectable object appears to be nearly the same color or brightness as its surroundings
If a detectable object cuts or suddenly emerges in front of your vehicle
When the front of your vehicle is hit by water, snow, dust, etc.
When a very bright light ahead, such as the sun or the headlights of oncoming traffic, shines directly into the forward recognition camera
When approaching the side or front of a vehicle ahead
If a vehicle ahead is a bicycle* or motorcycle
If a vehicle ahead is narrow, such as a personal mobility vehicle
If a preceding vehicle has a small rear end, such as an unloaded truck
If a preceding vehicle has a low rear end, such as a low bed trailer
If a vehicle ahead has extremely high ground clearance
If a vehicle ahead is carrying a load which protrudes past its rear bumper
If a vehicle ahead is irregularly shaped, such as a tractor or side car
If a vehicle ahead is a child sized bicycle, a bicycle that is carrying a large load, a bicycle ridden by more than one person, or a uniquely shaped bicycle (bicycle with a child seat, tandem bicycle, etc.)*
If a pedestrian/or the riding height of a bicyclist ahead is shorter than approximately 3.2 ft. (1 m) or taller than approximately 6.5 ft. (2 m)*
If a pedestrian/bicyclist is wearing oversized clothing (a rain coat, long skirt, etc.), making their silhouette obscure*
If a pedestrian is bending forward or squatting or bicyclist is bending forward*
When a pedestrian/bicyclist is moving fast*
If a pedestrian is pushing a stroller, wheelchair, bicycle or other vehicle*
When driving in inclement weather such as heavy rain, fog, snow or a sandstorm
When driving through steam or smoke
When the surrounding area is dim, such as at dawn or dusk, or while at night or in a tunnel, making a detectable object appear to be nearly the same color as its surroundings
When driving in a place where the surrounding brightness changes suddenly, such as at the entrance or exit of a tunnel
After the hybrid system has started the vehicle has not been driven for a certain amount of time
While making a left/right turn and for a few seconds after making a left/right turn
While driving on a curve and for a few seconds after driving on a curve
If your vehicle is skidding
If the front of the vehicle is raised or lowered
When the wheels are misaligned
If a wiper blade is blocking the forward recognition camera
The vehicle is being driven at extremely high speeds
When driving on a hill
If the millimeter wave radar sensor assembly or forward recognition camera is misaligned

*: Applicable to vehicles designed for countries/areas that detection of pedestrians and/or bicyclists is possible

(c) In some situations such as the following, sufficient braking force may not be obtained, preventing the system from performing properly:

If the braking functions cannot operate to their full extent, such as when the brake parts are extremely cold, extremely hot, or wet
If the vehicle is not properly maintained (brakes or tires are excessively worn, improper tire inflation pressure, etc.)
If the vehicle is being driven on a gravel road or other slippery surface

(d) If VSC is disabled, the pre-collision system performs the following:

Disables the pre-collision brake assist and pre-collision braking functions.
Turns on the PCS warning light.
Displays "VSC Turned Off Pre-collision Brake System Unavailable" on the multi-information display.

PRECAUTION BEFORE SERVICING

(a) When to disable the pre-collision system

In the following situations, disable the system, as it may not operate properly, possibly leading to an accident resulting in death or serious injury:

When the vehicle is being towed
When your vehicle is towing another vehicle
When transporting the vehicle via truck, boat, train or similar means of transportation
When the vehicle is raised on a lift with the hybrid system on and the tires are allowed to rotate freely
When inspecting the vehicle using a drum tester such as a chassis dynamometer or speedometer tester, or when using an on vehicle wheel balancer
When a strong impact is applied to the front bumper or front grille, due to an accident or other reasons
If the vehicle cannot be driven in a stable manner, such as when the vehicle has been in an accident or is malfunctioning
When the vehicle is driven in a sporty manner or off-road
When the tires are not properly inflated
When the tires are very worn
When tires of a size other than specified are installed
When tire chains are installed
When a compact spare tire or an emergency tire puncture repair kit is used
If equipment (snow plow, etc.) that may obstruct the millimeter wave radar sensor assembly or forward recognition camera is temporarily installed to the vehicle

TROUBLESHOOTING PRECAUTIONS

(a) If a malfunction related to terminal contact or part installation occurs, removal and reinstallation of the suspected part may return the system to normal. However, this the normal condition may only be temporary.

(b) When determining the malfunctioning area, before disconnecting connectors or removing/installing parts, check for DTCs and note the vehicle condition and operations that were performed when the malfunction occurred (stored DTCs, etc.).

(c) Be sure to check for DTCs related to other systems. The pre-collision system may be influenced by malfunctions in other systems.

HANDLING PRECAUTIONS

(a) When removing or installing any ECUs or sensors, make sure that the power switch is off unless otherwise specified in the procedure.

(b) After removing and installing any ECUs or sensor, make sure to check for DTCs and confirm that no DTCs are output.

PRECAUTION WHEN REPLACING COMPONENTS

(a) Millimeter Wave Radar Sensor Assembly:

(1) When replacing the millimeter wave radar sensor assembly, always replace it with a new one. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle and a DTC may be stored.

(2) When the millimeter wave radar sensor assembly has been replaced with a new one, it is necessary to perform millimeter wave radar sensor assembly adjustment and front radar acceleration sensor calibration, and to clear the vehicle control history.

Click here

(b) Forward Recognition Camera:

(1) When the forward recognition camera has been replaced with a new one or the windshield glass has been removed and installed, it is necessary to perform forward recognition camera adjustment and to clear the vehicle control history.

HINT:

Forward recognition camera adjustment can be performed by using either One Time Recognition or Sequential Recognition. When clearing vehicle control history, refer to the following links:

One Time Recognition: Click here

Sequential Recognition: Click here

(2) When replacing the forward recognition camera, always replace it with a new one. If a forward recognition camera which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle and a DTC may be stored.

(3) When replacing the forward recognition camera, do not damage the camera lens or allow it to become contaminated with foreign matter.

(4) Do not reuse a forward recognition camera that has been dropped or subjected to a strong impact.

(1) When replacing the windshield glass of a vehicle equipped with a forward recognition camera, make sure to use a Toyota genuine part. If a non-Toyota genuine part is used, the forward recognition camera may not be able to be installed due to a missing bracket or the pre-collision system may not operate properly due to a difference in the transmissivity or black ceramic border.

(2) Do not attach stickers, including transparent stickers, or other items to the windshield glass near the forward recognition camera.

PRECAUTIONS FOR RECORDED DATA

(a) The pre-collision system records data related to vehicle control and operation. Make sure to clear the data if requested by the customer.

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