Toyota Avalon (XX50): Window Defogger System(for Gasoline Model)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Vehicle Exterior / Window / Glass / Window Defogger System(for Gasoline Model)

Data List / Active Test

DATA LIST / ACTIVE TEST

ACTIVE TEST

HINT:

Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(d) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

Body Electrical > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Defogger Relay (Rear)	Rear window defogger wire (Back Window glass)	OFF or ON	-

Diagnosis System

DIAGNOSIS SYSTEM

CHECK DLC3

(a) Check the DLC3.

Click here

INSPECT BATTERY VOLTAGE

(a) Measure the battery voltage.

Standard Voltage:

11 to 14 V

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

How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT

HINT:

Use the following procedure to troubleshoot the window defogger system.
*: Use the Techstream.

PROCEDURE

1.	VEHICLE BROUGHT TO WORKSHOP

2.	CUSTOMER PROBLEM ANALYSIS

HINT:

In troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.
Gather as much information as possible for reference. Past problems that seem unrelated may also help in some cases.

The following 5 items are important points for problem analysis:

What	Vehicle model, system name
When	Date, time, occurrence frequency
Where	Road conditions
Under what conditions?	Driving conditions, weather conditions
How did it happen?	Problem symptoms

PRE-CHECK

(a) Measure the battery voltage.

Standard Voltage:

11 to 14 V

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

(b) Check the fuses and relays.

(c) Check the connector connections and terminals to make sure that there are no abnormalities such as loose connections, deformation, etc.

(d) Check the vehicle specifications.

4.	CHECK COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM*

(a) Using the Techstream, check for CAN communication system DTCs.

Click here

Result	Proceed to
CAN DTCs are not output	A
CAN DTCs are output	B

GO TO CAN COMMUNICATION SYSTEM

5.	PROBLEM SYMPTOMS TABLE

(a) Refer to Problem Symptoms Table.

Click here

Result	Proceed to
Fault is not listed in Problem Symptoms Table	A
Fault is listed in Problem Symptoms Table	B

GO TO STEP 7

6.	OVERALL ANALYSIS AND TROUBLESHOOTING*

(a) Operation Check

Click here

(b) Terminals of ECU

Click here

(d) On-vehicle Inspection

7.	REPAIR OR REPLACE

8.	CONFIRMATION TEST

END

Operation Check

OPERATION CHECK

CHECK WINDOW DEFOGGER SYSTEM

(a) Turn the engine switch on (IG).

(b) Check that the rear window defogger wire becomes warm by operating the rear window defogger switch of the radio and display receiver assembly.

NOTICE:

If the battery voltage becomes low, battery load control will operate in order to ensure sufficient power is supplied to the power steering system. In this case, the window defogger system may not operate.

HINT:

If both of the following conditions are met approximately 15 minutes after the window defogger system was activated, the window defogger system will continue to operate up to approximately 45 minutes. If the following conditions are not met, the window defogger system stops operating immediately.
- The outside temperature is -3°C (27°F) or lower.
- Power generated by the generator assembly is stable.
The window defogger system is linked with the mirror heater function.

Parts Location

PARTS LOCATION

ILLUSTRATION

DEF RELAY

REAR WINDOW DEFOGGER WIRE

NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY

-DEF FUSE

BACK WINDOW GLASS

ILLUSTRATION

REAR WINDOW DEFOGGER SWITCH (RADIO AND DISPLAY RECEIVER ASSEMBLY)

DLC3

AIR CONDITIONING AMPLIFIER ASSEMBLY

INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

- ECU-IG1 NO. 3 FUSE

Precaution

PRECAUTION

PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL

NOTICE:

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

System Name	See Procedure
Lane Departure Alert System (w/ Steering Control)
Intelligent Clearance Sonar System
Parking Assist Monitor System
Panoramic View Monitor System
Pre-collision System
Lighting System (for Gasoline Model with Cornering Light)

Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

HINT:

Inspect the fuses and relays related to this system before inspecting the suspected areas below.
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.

Window Defogger System

Symptom	Suspected Area	Link
Window defogger system does not operate	Proceed to the "Rear Window Defogger System does not Operate"

Rear Window Defogger System does not Operate

DESCRIPTION

When the rear window defogger switch on the radio and display receiver assembly is pressed, the operation signal is transmitted to the air conditioning amplifier assembly via CAN communication. When the air conditioning amplifier assembly receives the signal, it turns on the DEF relay to operate the window defogger system.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.
If the battery voltage becomes low, battery load control will operate in order to ensure sufficient power is supplied to the power steering system. In this case, the window defogger system may not operate.

PROCEDURE

1.	CHECK AIR CONDITIONING SYSTEM

(a) Check the air conditioning system.

HINT:

Both the window defogger system operation signal and air conditioning system operation signal are transmitted to the air conditioning amplifier assembly via the same communication line.

OK:

The air conditioning system operates normally.

GO TO AIR CONDITIONING SYSTEM

2.	PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(d) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

Body Electrical > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Defogger Relay (Rear)	Rear window defogger wire (Back window glass)	OFF or ON	-

Body Electrical > Air Conditioner > Active Test

Tester Display
Defogger Relay (Rear)

OK:

The window defogger system operates normally.

GO TO STEP 4

3.	REPLACE REAR WINDOW DEFOGGER SWITCH (RADIO AND DISPLAY RECEIVER ASSEMBLY)

(a) Replace the rear window defogger switch (radio and display receiver assembly) with a new or known good one.

Click here

(b) Check that the window defogger system operates normally.

Click here

OK:

The window defogger system operates normally.

END (REAR WINDOW DEFOGGER SWITCH (RADIO AND DISPLAY RECEIVER ASSEMBLY) WAS DEFECTIVE)

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

4.	INSPECT DEF RELAY

(a) Inspect the DEF relay.

Click here

REPLACE DEF RELAY

5.	CHECK HARNESS AND CONNECTOR (DEF RELAY - IG1-NO. 1 RELAY AND BATTERY)

(a) Remove the DEF relay from the No. 1 engine room relay block and No. 1 junction block assembly.

*a	DEF Relay Holder

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
DEF relay holder terminal 2 - Body ground	Engine switch on (IG)	11 to 14 V
DEF relay holder terminal 5 - Body ground	Always	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HARNESS AND CONNECTOR (DEF RELAY - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Remove the DEF relay from the No. 1 engine room relay block and No. 1 junction block assembly.

*a	DEF Relay Holder

(b) Disconnect the G35 air conditioning amplifier assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
DEF relay holder terminal 1 - G35-5 (RDFG)	Always	Below 1 Ω
DEF relay holder terminal 1 or G35-5 (RDFG) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	CHECK HARNESS AND CONNECTOR (DEF RELAY - REAR WINDOW DEFOGGER WIRE (BACK WINDOW GLASS))

(a) Remove the DEF relay from the No. 1 engine room relay block and No. 1 junction block assembly.

*a	DEF Relay Holder

(b) Disconnect the K21 rear window defogger wire (back window glass) wire connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
DEF relay holder terminal 3 - K21-1 (B)	Always	Below 1 Ω
DEF relay holder terminal 3 or K21-1 (B) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

8.	CHECK HARNESS AND CONNECTOR (REAR WINDOW DEFOGGER WIRE (BACK WINDOW GLASS) - BODY GROUND)

(a) Disconnect the L1 rear window defogger wire (back window glass) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
L1-1 (L) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

9.	CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Reconnect the G35 air conditioning amplifier assembly connector.

*a	Component with harness connected (Air Conditioning Amplifier Assembly)

(b) Reinstall the DEF relay.

Click here

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
G35-5 (RDFG) - G35-4 (GND)	Engine switch on (IG), rear window defogger switch on	Below 1 V
G35-5 (RDFG) - G35-4 (GND)	Engine switch on (IG), rear window defogger switch off	11 to 14 V

REPAIR OR REPLACE BACK WINDOW GLASS

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

System Description

SYSTEM DESCRIPTION

GENERAL

(a) The rear window defogger wire (back window glass) is attached to the inside of the rear window and defogs the window surface quickly when the rear window defogger switch is pressed. The indicator light on the switch illuminates while the system is operating. This system automatically turns off after approximately 15 minutes.

NOTICE:

HINT:

If both of the following conditions are met after approximately 15 minutes from when the window defogger system was activated, the window defogger system continues to operate up to approximately 45 minutes. If the following conditions are not met, the window defogger system stops operating immediately.
- The outside temperature is -3°C (27°F) or lower.
- Power generated by the generator assembly installed to the vehicle is stable.
The window defogger system is linked with the mirror heater function.

FUNCTION OF MAIN COMPONENT

Component	Outline
Rear Window Defogger Switch (Radio and Display Receiver Assembly)	Sends signals to the air conditioning amplifier assembly to operate the window defogger system.
Air Conditioning Amplifier Assembly	Sends a window defogger system activation request signal to the DEF relay.
DEF Relay	Receives a window defogger system activation request signal from the air conditioning amplifier assembly and supplies power to the rear window defogger wire (back window glass).
Rear Window Defogger Wire (Back Window Glass)	Receives power from the DEF relay and heats the rear window using the rear window defogger wire (back window glass).

System Diagram

SYSTEM DIAGRAM

Communication Table

Transmitter	Receiver	Signal	Communication Method
Rear Window Defogger Switch (Radio and Display Receiver Assembly)	Air Conditioning Amplifier Assembly	Rear Window Defogger Switch Signal	CAN

Terminals Of Ecu

TERMINALS OF ECU

CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Disconnect the G35 air conditioning amplifier assembly connector.

(b) Measure the voltage and resistance according to the value(s) in the table below.

HINT:

Measure the values on the wire harness side with the connector disconnected.

Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
G35-2 (IG+) - G35-4 (GND)	LA-GR - W-B	Power source (IG)	Engine switch on (IG)	11 to 14 V
G35-2 (IG+) - G35-4 (GND)	LA-GR - W-B	Power source (IG)	Engine switch off	Below 1 V
G35-1 (B) - G35-4 (GND)	LA-B - W-B	Battery power supply	Always	11 to 14 V
G35-4 (GND) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω

(d) Measure the voltage according to the value(s) in the table below.

Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
G35-5 (RDFG) - G35-4 (GND)	L - W-B	Rear window defogger signal	Engine switch on (IG), rear window defogger switch off	11 to 14 V
G35-5 (RDFG) - G35-4 (GND)	L - W-B	Rear window defogger signal	Engine switch on (IG), rear window defogger switch on	Below 1 V

CHECK REAR WINDOW DEFOGGER SWITCH (RADIO AND DISPLAY RECEIVER ASSEMBLY)

Click here

Relay

Window Defogger System(for Hv Model)

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