Last Modified: 06-05-2026 6.11:8.1.0 Doc ID: RM100000001CO0N
Model Year Start: 2019 Model: Corolla Hatchback Prod Date Range: [06/2018 - 01/2019]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): Air Vent Temperature does not Change and Right Vent is Different from Left and Vice Versa (Same Left/Right Temperature Setting); 2019 MY Corolla Hatchback [06/2018 - 01/2019]

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)
  • Compressor assembly with pulley 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

CAUTION / NOTICE / HINT

NOTICE:

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 Corolla Corolla Hatchback [06/2018 - 09/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): HOW TO PROCEED WITH TROUBLESHOOTING

PROCEDURE

1.

CHECK WHEN MALFUNCTION OCCURS

Result

Result

Proceed to

When using cooling function

A

When using heater function

B
B

GO TO STEP 5

A

2.

CHECK FOR DTC

(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 / Main Body / Trouble Codes.

(e) Check for DTCs.

Body Electrical > Main Body > Trouble Codes

Result

Result

Proceed to

B1244 is not output

A

B1244 is output

B
B

GO TO DTC B1244

w/o AFS: Click here 2019 MY Corolla Hatchback [06/2018 - 01/2019]; LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model without AFS): B1244; Light Sensor Circuit

w/ AFS: Click here 2019 - 2022 MY Corolla Corolla Hatchback [06/2018 - 09/2022]; LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model with AFS): B1244; Light Sensor Circuit

A

3.

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

(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

Result

Amount of Refrigerant

Refrigerant correct

Correct

Refrigerant shortage

Insufficient

OK:

"Refrigerant correct" is displayed on the Techstream.

NG

CHARGE SYSTEM WITH REFRIGERANT

OK

4.

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 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 pulse

Min.: 128

Max.: 383

Operates between 165 and 257 pulses*
  • *: for Dual Type

Body Electrical > Air Conditioner > Active Test

Body Electrical > Air Conditioner > Active Test

OK:

Each damper servo motor operates.

OK

INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET

NG

GO TO DTC TROUBLESHOOTING PROCEDURE FOR MALFUNCTIONING DAMPER SERVO MOTOR

5.

BLEED AIR FROM COOLING SYSTEM

(a) Bleed air from cooling system.

Click here 2019 - 2020 MY Corolla Corolla Hatchback [06/2018 - 09/2019]; M20A-FKS (COOLING): COOLANT: REPLACEMENT

NEXT

6.

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

7.

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 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 pulse

Min.: 128

Max.: 383

Operates between 255 and 347 pulses*
  • *: for Dual Type

Body Electrical > Air Conditioner > Active Test

Body Electrical > Air Conditioner > Active Test

OK:

Each damper servo motor operates.

OK

REPLACE HEATER RADIATOR UNIT SUB-ASSEMBLY

NG

GO TO DTC TROUBLESHOOTING PROCEDURE FOR MALFUNCTIONING DAMPER SERVO MOTOR