Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

HINT:

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.
When an open circuit or frozen indication is displayed by the self-check function, check for DTCs and troubleshoot according to each inspection procedure.

General

Symptom	Suspected Area	Link
System does not operate at all	Proceed to "Clearance Warning ECU Power Source Circuit"
	CAN communication system
	Clearance warning ECU assembly
System cannot be turned off	CAN communication system
System cannot be turned off	Clearance warning ECU assembly

Sonar Function

Symptom	Suspected Area	Link
Combination meter assembly (shift selection) operates normally, but detection operates when shift lever is in P, or detection does not operate when shift lever is in any position other than P (front sonar)	CAN communication system
	Clearance warning ECU assembly
Combination meter assembly (shift selection) operates normally, but detection operates when shift lever is not in R, or does not operate with shift lever in R (rear sonar)	CAN communication system
	Clearance warning ECU assembly
Combination meter assembly (speedometer) operates normally, but detection does not operate when vehicle speed meets operation condition, or detection operates when vehicle speed does not meet operation condition (front sonar)	CAN communication system
	Clearance warning ECU assembly

Buzzer Function

Symptom	Suspected Area	Link
Sonar detection operation is normal but buzzer operation is intermittent	Check that the temporary mute function is not operating	-
	Proceed to "No. 1 Clearance Warning Buzzer Circuit"
	Proceed to "No. 2 Clearance Warning Buzzer Circuit"
	Clearance warning ECU assembly

Display Function

Symptom	Suspected Area	Link
Detection operation is normal but clearance sonar indicator does not illuminate	CAN communication system
	Combination meter assembly
	Clearance warning ECU assembly
Detection operation is normal but all sonar displays do not appear on multi-information display and multi-display	CAN communication system
	Clearance warning ECU assembly
Detection operation is normal but sonar displays do not appear on multi-information display	CAN communication system
	Combination meter assembly
	Clearance warning ECU assembly
Detection operation is normal but sonar displays do not appear on the full screen display (on the multi-display)	CAN communication system
	Radio and display receiver assembly
	Clearance warning ECU assembly
Detection operation is normal but sonar displays do not appear on the cooperated display (on the multi-display)*1	CAN communication system
	Radio and display receiver assembly
	Parking Assist ECU
	Clearance warning ECU assembly
Detection operation is normal but sonar displays do not appear on the cooperated display (on the multi-display)*2	CAN communication system
	Radio and display receiver assembly
	Television Camera Assembly
	Clearance warning ECU assembly
Detection operation is normal but sonar displays do not appear on the cooperated display (on the headup display)*3	CAN communication system
	Headup display (meter mirror sub-assembly)
	Clearance warning ECU assembly

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual > Lane Departure Alert System (w/ Steering Control)(for Gasoline Model): Driving Support ECU (C1A01)
DESCRIPTION If the forward recognition camera detects a malfunction in the internal circuit of the driving support ECU assembly, DTC C1A01 is stored. DTC No. Detection Item DTC Detection Condition Trouble Area C1A01 Driving Support ECU 2 seconds after the engine switch is turned on (IG), a malfuncti ...

Toyota Avalon (XX50) 2019-2022 Owners Manual