Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001A3OI
Model Year Start: 2019 Model: Avalon HV Prod Date Range: [04/2018 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): Cooling is Poor; 2019 - 2022 MY Avalon HV [04/2018 -        ]

Cooling is Poor

DESCRIPTION

If the cooling effect of the air conditioning system is weak, the following factors may be the cause.

Symptom

Factor
  • Cooling effectiveness is poor
  • Cooling response is slow
  • ECO mode control of air conditioning system is enabled
  • Compressor with motor assembly malfunction
  • Refrigerant volume (high)
  • Refrigerant volume (low)
  • Clogged cooler condenser assembly fins
  • Cooling fan system malfunction
  • Mechanical locking of damper and damper link
  • Automatic light control sensor malfunction
  • High inlet air temperature
  • Harness or connector

WIRING DIAGRAM

PROCEDURE

1.

CHECK ECO MODE SETTING

(a) Check if the ECO mode indicator is off.

OK:

The ECO mode indicator is off.

OK

GO TO STEP 3

NG

2.

CHECK ECO MODE CONTROL OPERATION

(a) Operate the ECO switch assembly (electric parking brake switch assembly) and check that the ECO mode indicator turns off and the blower speed reduction is canceled.

HINT:

  • When ECO mode control is operating, the air conditioning amplifier assembly controls the air conditioning system to enhance fuel efficiency. Therefore, explain to the customer that, when ECO mode control is operating, the blower speed will be reduced.

    Control

    Outline

    Blower Control

    When the air conditioning system is in AUTO mode, the blower speed will be reduced to a certain speed. Additionally, if warm-up control is operating, the blower speed will be further reduced.

    Air Inlet Control

    If the ambient temperature is a certain value or more, the air inlet mode will be changed to recirculation mode.
  • In some situations, ECO mode control may not operate even though it is enabled.

Result

Proceed to

ECO mode indicator turns off and blower speed reduction is canceled

A

ECO mode indicator turns off, but the blower speed reduction is not canceled

B

ECO mode indicator does not turn off
B

GO TO ECO Switch Circuit

A

3.

PERFORM REFRIGERANT SHORTAGE CHECK

(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 / 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

REPAIR REFRIGERANT LEAK

OK

4.

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.

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

OK

5.

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

6.

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