Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000001FPEB
Model Year Start: 2019 Model: RAV4 Prod Date Range: [11/2018 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): B1446; Air Mix Damper Control Servo Motor Circuit (Driver Side); 2019 - 2024 MY RAV4 [11/2018 -        ]

DTC

B1446

Air Mix Damper Control Servo Motor Circuit (Driver Side)

DESCRIPTION

The No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) to the appropriate position. This adjusts the amount of air passing through the heater core after passing the evaporator and controls the temperature of the output air. The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B1446

Air Mix Damper Control Servo Motor Circuit (Driver Side)
  • Diagnosis condition: During No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) operation
  • Malfunction status: The damper servo operation request signal is output but the position information of the servo does not change or servo is malfunctioning
  • Detection time: Continuously for 30 seconds or more
  • No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix)
  • Air conditioning harness assembly
  • Air conditioning radiator assembly
  • Air conditioning amplifier assembly

Memorized

DTC Detection Condition Combination Table

 

Vehicle Condition

Pattern 1

Pattern 2

Diagnosis Condition

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

○

○

Malfunction Status

The damper servo operation request signal is output but the position information of the servo does not change

○

-

The damper servo operation request signal is output but the position information of the servo is malfunctioning

-

○

Detection Time

Continuously for 30 seconds or more

Continuously for 30 seconds or more

Trip Count

1 trip

1 trip

HINT:

If the conditions match either of these patterns, a DTC will be output.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When DTC B1441, B1442, B1443 and B1446 are output at the same time, the No. 1 air conditioning radiator damper servo sub-assembly is malfunctioning.
  • Confirm that no mechanical problem is present because this diagnostic code can be output when either a damper link or the damper is mechanically locked.
  • When installing the servo motor, make sure to install it correctly.
  • When the servo motor is replaced, be sure to perform servo motor initialization.

    Click here 2019 - 2024 MY RAV4 [11/2018 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): INITIALIZATION

PROCEDURE

1.

CHECK FOR DTC

(a) Check for DTCs.

Click here 2019 - 2024 MY RAV4 [11/2018 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): DTC CHECK / CLEAR

Body Electrical > Air Conditioner > Trouble Codes

Result

Proceed to

DTC B1446 is output

A

DTC B1441, B1442, B1443 and B1446 are output

B
B

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY 2019 - 2020 MY RAV4 [11/2018 - 08/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): DISASSEMBLY 2021 - 2024 MY RAV4 [08/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): DISASSEMBLY

A

2.

CHECK FOR DTC

(a) Check for DTCs.

Click here 2019 - 2024 MY RAV4 [11/2018 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): DTC CHECK / CLEAR

Body Electrical > Air Conditioner > Trouble Codes

Result

Proceed to

DTC B1446 is output

A

DTC B1446 and B1497 are output

B
B

GO TO DTC B1497 2019 - 2020 MY RAV4 [11/2018 - 08/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): B1497; Communication Malfunction (Bus Ic) 2021 - 2024 MY RAV4 [08/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): B1497; Communication Malfunction (Bus Ic)

A

3.

CHECK NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY

(a) Check that the No. 1 air conditioning radiator damper servo sub-assembly is installed correctly.

OK:

No. 1 air conditioning radiator damper servo sub-assembly is installed correctly.

NG

REINSTALL NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY 2019 - 2020 MY RAV4 [11/2018 - 08/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): REASSEMBLY 2021 - 2024 MY RAV4 [08/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): REASSEMBLY

OK

4.

CHECK NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (MOTOR, LINK, DAMPER)

(a) Check for a wire harness caught between the links of the motors and dampers.

OK:

No wire harnesses are caught between the links of the motors and dampers.

NG

REMOVE PINCHED WIRE HARNESS
OK

5.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Using the Techstream, perform the following Active Test and read the Data List value.

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 to 257 pulses

Body Electrical > Air Conditioner > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Air Mix Servo Actual Pulse(D)

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

Min.: 128

Max.: 383
  • MAX COLD: 257 (pulse)
  • MAX HOT: 165 (pulse)

-

Body Electrical > Air Conditioner > Active Test

Active Test Display

Air Mix Servo Targ Pulse(D)

Data List Display

Air Mix Servo Actual Pulse(D)

OK:

The value of the Data List changes in accordance with the operation of the Active Test.

NG

GO TO STEP 9

OK

6.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Using the Techstream, perform the following Active Test and read the Data List value.

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 to 257 pulses

Body Electrical > Air Conditioner > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Air Mix Servo Targ Pulse(D)

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

Min.: 128

Max.: 383
  • MAX COLD: 257 (pulse)
  • MAX HOT: 165 (pulse)

-

Air Mix Servo Actual Pulse(D)

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

Min.: 128

Max.: 383
  • MAX COLD: 257 (pulse)
  • MAX HOT: 165 (pulse)

-

Body Electrical > Air Conditioner > Active Test

Active Test Display

Air Mix Servo Targ Pulse(D)

Data List Display

Air Mix Servo Targ Pulse(D)

Air Mix Servo Actual Pulse(D)

OK:

The target pulse value of the Data List matches the actual pulse.

OK

USE SIMULATION METHOD TO CHECK

NG

7.

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY

HINT:

Click here 2019 - 2020 MY RAV4 [11/2018 - 08/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): DISASSEMBLY 2021 - 2024 MY RAV4 [08/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): DISASSEMBLY

NEXT

8.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Using the Techstream, perform the following Active Test and read the Data List value.

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 to 257 pulses

Body Electrical > Air Conditioner > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Air Mix Servo Actual Pulse(D)

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

Min.: 128

Max.: 383
  • MAX COLD: 257 (pulse)
  • MAX HOT: 165 (pulse)

-

Body Electrical > Air Conditioner > Active Test

Active Test Display

Air Mix Servo Targ Pulse(D)

Data List Display

Air Mix Servo Actual Pulse(D)

OK:

The value of the Data List changes in accordance with the operation of the Active Test.

OK

END
NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY 2019 - 2020 MY RAV4 [11/2018 - 08/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): DISASSEMBLY 2021 - 2024 MY RAV4 [08/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): DISASSEMBLY

9.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Using the Techstream, perform the following Active Test and read the Data List value.

Body Electrical > Air Conditioner > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Air Outlet Servo Pulse (D)

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

Min.: 128

Max.: 383

Operates between 241 to 348 pulses

Body Electrical > Air Conditioner > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Air Outlet Servo Actu Pulse(D)

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

Min.: 128

Max.: 383
  • FACE-R: 241 (pulse)
  • FACE: 256 (pulse)
  • FACE 1: 256 (pulse)
  • FACE 2: 256 (pulse)
  • B/L: 267 (pulse)
  • B/L 2: 267 (pulse)
  • FOOT-0: 288 (pulse)
  • FOOT-R: 297 (pulse)
  • FOOT: 297 (pulse)
  • FOOT-D: 305 (pulse)
  • F/D: 320 (pulse)
  • DEF-FOOT: 339 (pulse)
  • DEF or Close: 348 (pulse)

-

Body Electrical > Air Conditioner > Active Test

Active Test Display

Air Outlet Servo Pulse (D)

Data List Display

Air Outlet Servo Actu Pulse(D)

OK:

The value of the Data List changes in accordance with the operation of the Active Test.

OK

GO TO STEP 7

NG

10.

CHECK AIR CONDITIONING RADIATOR ASSEMBLY (DAMPER)

(a) Remove the No. 1 air conditioning radiator damper servo sub-assembly.

Click here 2019 - 2020 MY RAV4 [11/2018 - 08/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): DISASSEMBLY 2021 - 2024 MY RAV4 [08/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for A25A-FKS): DISASSEMBLY

(b) Operate the dampers by hand.

OK:

The dampers are easily operated by hand.

OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPLACE AIR CONDITIONING RADIATOR ASSEMBLY