Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM1000000019XOJ
Model Year Start: 2019 Model: Avalon Prod Date Range: [04/2018 - 08/2020]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): Air Vent Temperature does not Change and Right Vent is Different from Left and Vice Versa (Same Left/Right Temperature Setting); 2019 - 2020 MY Avalon [04/2018 - 08/2020]

Air Vent Temperature does not Change and Right Vent is Different from Left and Vice Versa (Same Left/Right Temperature Setting)

DESCRIPTION

If the temperature of the air that blows from the left and right front registers differs, even though the same temperature is set for both sides, the following factors may be the cause.

Symptom

Factor

Temperature of outlet air is cooler on left or right side

  • (when same temperature set for both sides)
  • Cooler compressor assembly (compressor solenoid) malfunction
  • Refrigerant volume (low)
  • Mechanical locking of damper and damper link
  • Automatic light control sensor malfunction
  • Harness or connector

Temperature of outlet air is warmer on left or right side

  • (when same temperature set for both sides)
  • Mechanical locking of damper and damper link
  • Blockage in heater radiator unit sub-assembly
  • Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • If DTC B1244 is output, troubleshoot for DTC B1244 first.

    w/ Cornering Light: Click here 2019 - 2022 MY Avalon [04/2018 -        ]; LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model with Cornering Light): B1244; Light Sensor Circuit

    w/o Cornering Light: Click here 2019 - 2022 MY Avalon [04/2018 -        ]; LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model without Cornering Light): B1244; Light Sensor Circuit

  • The air conditioning system uses the CAN communication system. Inspect the communication functions by following How to Proceed with Troubleshooting. Troubleshoot the air conditioning system after confirming that the communication systems are functioning properly.

    Click here 2019 - 2022 MY Avalon [04/2018 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): HOW TO PROCEED WITH TROUBLESHOOTING

PROCEDURE

1.

CHECK WHEN MALFUNCTION OCCURS

Result

Proceed to

When using cooling function

A

When using heater function

B
B

GO TO STEP 6

A

2.

PERFORM REFRIGERANT SHORTAGE CHECK

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Utility / Refrigerant Gas Volume Check.

Body Electrical > Air Conditioner > Utility

Tester Display

Refrigerant Gas Volume Check

(e) Check that the following conditions are met and perform the refrigerant shortage check according to the display on the Techstream.

Measurement Condition:

Item

Condition

A/C switch

On

Ambient temperature*

0 to 49°C (32 to 120°F)

Blower speed

HI

*: If the ambient temperature is not within the range shown, do not perform this check.

Result

Amount of Refrigerant

Refrigerant correct

Correct

Refrigerant shortage

Insufficient

OK:

"Refrigerant correct" is displayed on the Techstream.

NG

CHARGE SYSTEM WITH REFRIGERANT

OK

3.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(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

Air Mix Servo Targ Pulse(D)

No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) pulse

Min.: 128

Max.: 383

Operates between 165 and 257 pulses

Air Mix Servo Targ Pulse(P)

No. 1 air conditioning radiator damper servo sub-assembly (front passenger side air mix) pulse

Min.: 128

Max.: 383

Operates between 255 and 347 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Mix Servo Targ Pulse(D)

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Mix Servo Targ Pulse(P)

OK:

Each damper servo motor operates.

NG

GO TO DTC TROUBLESHOOTING PROCEDURE FOR MALFUNCTIONING DAMPER SERVO MOTOR

OK

4.

CHECK HARNESS AND CONNECTOR (AUTOMATIC LIGHT CONTROL SENSOR - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Disconnect the G23 automatic light control sensor connector.

(b) Disconnect the G33 main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G23-1 (CLTB) - G33-23 (CLTB)

Always

Below 1 Ω

G23-2 (CLTE) - G33-25 (CLTE)

Always

Below 1 Ω

G23-4 (CLTS) - G33-24 (CLTS)

Always

Below 1 Ω

G23-1 (CLTB) or G33-23 (CLTB) - Other terminals and body ground

Always

10 kΩ or higher

G23-2 (CLTE) or G33-25 (CLTE) - Other terminals and body ground

Always

10 kΩ or higher

G23-4 (CLTS) or G33-24 (CLTS) - Other terminals and body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

INSPECT AUTOMATIC LIGHT CONTROL SENSOR

(a) Remove the automatic light control sensor.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; HEATING / AIR CONDITIONING: SOLAR SENSOR: REMOVAL

(b) Inspect the automatic light control sensor.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; HEATING / AIR CONDITIONING: SOLAR SENSOR: ON-VEHICLE INSPECTION

OK

INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET

NG

REPLACE AUTOMATIC LIGHT CONTROL SENSOR

6.

BLEED AIR FROM COOLING SYSTEM

(a) Bleed air from cooling system.

Click here 2019 - 2022 MY Avalon [04/2018 -        ]; 2GR-FKS (COOLING): COOLANT: REPLACEMENT

NEXT

7.

CHECK OPERATION (AIR CONDITIONING SYSTEM)

(a) Set the same temperature for the left and right sides and check that the air that blows from the left and right front registers is the same temperature.

OK:

The air from the left and right front registers is the same temperature.

OK

END (MALFUNCTION DUE TO AIR IN COOLING SYSTEM)
NG

8.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(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

Air Mix Servo Targ Pulse(D)

No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) pulse

Min.: 128

Max.: 383

Operates between 165 and 257 pulses

Air Mix Servo Targ Pulse(P)

No. 1 air conditioning radiator damper servo sub-assembly (front passenger side air mix) pulse

Min.: 128

Max.: 383

Operates between 255 and 347 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Mix Servo Targ Pulse(D)

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Mix Servo Targ Pulse(P)

OK:

Each damper servo motor operates.

OK

REPLACE HEATER RADIATOR UNIT SUB-ASSEMBLY 2019 MY Avalon [04/2018 - 08/2019]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for Gasoline Model): DISASSEMBLY 2020 - 2022 MY Avalon [08/2019 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for Gasoline Model): DISASSEMBLY

NG

GO TO DTC TROUBLESHOOTING PROCEDURE FOR MALFUNCTIONING DAMPER SERVO MOTOR