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