Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001JSM4
Model Year Start: 2020 Model: Avalon HV Prod Date Range: [08/2019 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): No Warm Air Comes Out; 2020 - 2022 MY Avalon HV [08/2019 -        ]

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
  • Flow shutting valve (water by-pass hose assembly) malfunction

PROCEDURE

1.

CHECK FOR DTC

(a) Check for DTCs.

Powertrain > Engine > Trouble Codes

OK:

SFI system DTCs are not output.

NG

GO TO SFI SYSTEM 2020 MY Avalon HV [08/2019 - 08/2020]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DIAGNOSTIC TROUBLE CODE CHART 2021 MY Avalon HV [08/2020 - 08/2021]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DIAGNOSTIC TROUBLE CODE CHART 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DIAGNOSTIC TROUBLE CODE CHART

OK

2.

READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

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

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

Powertrain > Engine > Data List

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).

Powertrain > Engine > Data List

Tester Display

Coolant Temperature

OK:

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

NG

GO TO COOLING SYSTEM

OK

3.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the power 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

NG

GO TO DTC TROUBLESHOOTING PROCEDURE FOR MALFUNCTIONING DAMPER SERVO MOTOR 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): DIAGNOSTIC TROUBLE CODE CHART 2021 - 2022 MY Avalon HV [08/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): DIAGNOSTIC TROUBLE CODE CHART