TOYOTA PARKING ASSIST-SENSOR SYSTEM(for 4 Sensor Type) PROBLEM SYMPTOMS TABLE

Tech Tips

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.

General
Symptom	Suspected Area	Link
System does not operate at all (Initial check function also does not operate)	Proceed to "Clearance Warning ECU Power Source Circuit"	Click here
	Clearance warning ECU assembly (for LHD)	Click here
	Clearance warning ECU assembly (for RHD)	Click here

Sonar Function
Symptom	Suspected Area	Link
Clearance warning indicator indicates rear corner clearance sonar sensor is frozen	Clean sensor surface	Click here
	Proceed to "Rear Clearance Sonar Sensor LH Circuit"	Click here
	Proceed to "Rear Clearance Sonar Sensor RH Circuit"	Click here
	Proceed to "Back Sonar Sensor LH Circuit"	Click here
	Proceed to "Back Sonar Sensor RH Circuit"	Click here
	Replace clearance warning ECU assembly (for LHD)	Click here
	Replace clearance warning ECU assembly (for RHD)	Click here
Clearance warning indicator indicates rear center sonar sensor is frozen	Clean sensor surface	Click here
	Proceed to "Back Sonar Sensor LH Circuit"	Click here
	Proceed to "Back Sonar Sensor RH Circuit"	Click here
	Proceed to "Rear Clearance Sonar Sensor LH Circuit"	Click here
	Replace clearance warning ECU assembly (for LHD)	Click here
	Replace clearance warning ECU assembly (for RHD)	Click here
Clearance warning indicator indicates open in rear clearance sonar sensor circuit	Initial check function	Click here
	Proceed to "Rear Clearance Sonar Sensor LH Circuit"	Click here
	Proceed to "Rear Clearance Sonar Sensor RH Circuit"	Click here
	Proceed to "Back Sonar Sensor LH Circuit"	Click here
	Proceed to "Back Sonar Sensor RH Circuit"	Click here
	Replace clearance warning ECU assembly (for LHD)	Click here
	Replace clearance warning ECU assembly (for RHD)	Click here
Clearance sonar sensors operate when shift lever is not in R, or do not operate even when shift lever is in R	Proceed to "Reverse Signal Circuit"	Click here
	Replace clearance warning ECU assembly (for LHD)	Click here
	Replace clearance warning ECU assembly (for RHD)	Click here

Buzzer Function
Symptom	Suspected Area	Link
Clearance warning buzzer continues to sound indicating a malfunction while the system is on	Precaution	Click here
	Proceed to "Clearance Warning Buzzer Circuit"	Click here
	Replace clearance warning ECU assembly (for LHD)	Click here
	Replace clearance warning ECU assembly (for RHD)	Click here

Indicator Function
Symptom	Suspected Area	Link
Indicator does not dim at night, or illuminates dimly during daytime	Proceed to "Taillight Relay Circuit"	Click here
	Replace clearance warning ECU assembly (for LHD)	Click here
	Replace clearance warning ECU assembly (for RHD)	Click here
Detection operation is normal but clearance warning indicator does not illuminate	Proceed to "Indicator Circuit"	Click here
	Telltale light assembly	Click here
	Replace clearance warning ECU assembly (for LHD)	Click here
	Replace clearance warning ECU assembly (for RHD)	Click here