HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): No Warm Air Comes Out; 2019 - 2020 MY Avalon [04/2018

Last Modified: 08-21-2023	6.11:8.1.0	Doc ID: RM1000000019XOR
Model Year Start: 2019	Model: Avalon	Prod Date Range: [04/2018 - 08/2020]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): No Warm Air Comes Out; 2019 - 2020 MY Avalon [04/2018 - 08/2020]

No Warm Air Comes Out

DESCRIPTION

If cool air blows from the registers regardless of the temperature setting of the air conditioning system, the following factors may be the cause.

Symptom	Factor
No warm air comes out (Blower control is normal) Outlet air temperature does not increase (Blower control is normal)	Engine coolant temperature (low) Refrigerant volume (low) No. 1 air conditioning radiator damper servo sub-assembly malfunction Warm-up control Blockage in heater radiator unit sub-assembly Heater radiator unit sub-assembly malfunction

1.	READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

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

(d) Enter the following menus: Powertrain / Engine / Data List.

(e) Read the Data List according to the display on the Techstream.

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Coolant Temperature	Engine coolant temperature	Min.: -40°C (-40°F), Max.: 140°C (284°F)	75 to 100°C (167 to 212°F): After warming up	This is the engine coolant temperature. HINT: After warming up the engine, the engine coolant temperature will be 75 to 100°C (167 to 212°F). After a long soak, the engine coolant temperature, intake air temperature and ambient air temperature will be approximately equal. If the value is -40°C (-40°F), or higher than 135°C (275°F), the sensor circuit is open or shorted. Check if the engine overheats if the value indicated is higher than 135°C (275°F).

Tester Display
Coolant Temperature

OK:

After warming up the engine, the temperature value displayed is within the range specified in the normal condition column.

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.

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

Tester Display
Air Mix Servo Targ Pulse(D)

Tester Display
Air Mix Servo Targ Pulse(P)

OK:

Each damper servo motor operates.

REPLACE HEATER RADIATOR UNIT SUB-ASSEMBLY