Toyota FJ Cruiser (GSJ 10, 15 series). Instruction — part 345

PM–4

PARK ASSIST / MONITORING – CLEARANCE SONAR SYSTEM

PM

SYSTEM DIAGRAM

Clearance
Warning
ECU

Clearance Warning Buzzer

No. 1 Ultrasonic Sensor (LH)

No. 1 Ultrasonic Sensor (RH)

Back Sonar Switch

Park/Neutral Position Switch

*2

Back-up Light Switch

*1

*2: For Automatic Transmission

*1: For Manual Transmission

I102679E01

PARK ASSIST / MONITORING – CLEARANCE SONAR SYSTEM

PM–5

PM

SYSTEM DESCRIPTION

1.

GENERAL
(a) This system uses ultrasonic sensors to detect

obstacles at the rear of the vehicle. The system then
informs the driver of the approximately distance
between the sensors and the obstacles by sounding
a buzzer.

2.

FUNCTIONS OF COMPONENTS

3.

OPERATION EXPLANATION
(a) The clearance warning ECU determines whether

the clearance sonar system should operate or not
based on the back sonar switch on/off status and
the shift lever position.

(b) When the system operates, the clearance warning

ECU transmits ultrasonic waves from the ultrasonic
sensor. If an obstacle is detected within a sensor's
detection range, the waves are reflected back to the
sensors. The sensor then transmits a signal to the
clearance warning ECU. Based on this information,
the clearance warning ECU sends signals to the
clearance warning buzzer. The approximate
distance between the vehicle and the obstacle is
then communicated through different types of
buzzer sounds.
HINT:
Refer to "OPERATION CHECK" for detailed
operation (See page

PM-7

).

4.

NOTE FOR CLEARANCE SONAR SYSTEM
(a) Under the following conditions, the ultrasonic sensor

may not operate properly.
(1) Foreign matter such as snow or mud is on

sensor (the detection function returns to normal
if foreign matter is cleared away).

(2) The sensor is frozen (the detection function

returns to normal if defrosted).
HINT:
Especially in cold weather, the sensor may not
be able to detect obstacles if it is frozen or
otherwise affected by the weather.

(b) The detection range of the ultrasonic sensor may be

affected by the following condition:
(1) Foreign matter such as snow or mud is on the

sensor.

Components

Function

Ultrasonic Sensor

Detects distance between vehicle and obstacle

Back Sonar Switch

Turns the clearance sonar system on and off

Clearance Warning Buzzer

Emits an intermittent sound to inform the driver that the ECU has detected an

obstacle within prescribed ranges

Clearance Warning ECU

•

Judges approximate distance between vehicle and obstacle

•

ECU has buzzer sound volume adjusting knob

Park / Neutral Position Switch (A/T)

Sends a signal that activates the clearance sonar system when the shift lever is

moved to the R position

Back-up Light Switch (M/T)

Transmits reverse shift position signal to clearance warning ECU

PM–6

PARK ASSIST / MONITORING – CLEARANCE SONAR SYSTEM

PM

(2) In very hot or cold weather.

(c) Under the following conditions, the clearance sonar

system may detect an error.
(1) Another vehicle's horn, motorcycle engine

sounds, an approaching vehicle's air brake
sound, or other things that generate ultrasonic
waves are near the vehicle.

(2) The vehicle gets caught in a downpour, or mud

or water splashes onto the vehicle's body.

(3) The vehicle is severely tilted.
(4) The vehicle is equipped with a commercial

fender pole.

(5) Foreign matter such as snow or mud is on the

sensor.

(6) A vehicle equipped with a sonar system is in the

vicinity.

(7) The vehicle is equipped with a towing hook.

(d) The clearance sonar system cannot detect the

following objects:
(1) Thin objects like wires, ropes or poles.
(2) Materials that easily absorb the ultrasonic waves

such as cotton, snow, etc.

(3) Objects with sharp edges.
(4) Short objects.
(5) Tall objects with a protruding or overhanging

upper part.

(e) Other conditions

(1) The sensor cannot detect an object under the

bumper. Also, the sensor may detect an object
and then lose track of the object if: 1) the object
starts out in the detection range and then ends
up below the sensor, or 2) the object is a thin
pole, such as a picket.

(2) The sensor may be unable to detect objects

when the sensor is too close to the objects.

(3) The sensor may not operate properly if it is

dropped or subjected to a strong impact.

PARK ASSIST / MONITORING – CLEARANCE SONAR SYSTEM

PM–7

PM

HOW TO PROCEED WITH
TROUBLESHOOTING

NEXT

Standard voltage:

11 to 14 V

If the voltage is below 11 V, recharge or replace the battery
before proceeding.

NEXT

Result

B

A

(a) Operation check (See page

PM-7

).

(b) Terminals of ECU (See page

PM-11

).

NEXT

NEXT

NEXT

1

VEHICLE BROUGHT TO WORKSHOP

2

INSPECT BATTERY VOLTAGE

3

PROBLEM SYMPTOMS TABLE

Result

Proceed to

Fault is not listed in problem symptoms table

A

Fault is listed in problem symptoms table

B

Go to step 5

4

OVERALL ANALYSIS AND TROUBLESHOOTING

5

ADJUST, REPAIR OR REPLACE

6

CONFIRMATION TEST

END