Vehicle Interior

Air Outlet Damper Control Servo Motor Circuit (B1443/43)

~3min read
DESCRIPTION

The damper servo sub-assembly (mode damper servo) sends pulse signals to inform the No. 1 air conditioning amplifier assembly of the damper position. The No. 1 air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air outlet damper to any position, which controls the air outlet changes.

HINT:

Confirm that no mechanical problem is present because this trouble code may be stored when either a damper link or damper is mechanically locked.

DTC Code

DTC Detection Condition

Trouble Area

B1443/43

The air outlet damper position does not change when the No. 1 air conditioning amplifier assembly operates the damper servo sub-assembly (mode damper servo).

  • Damper servo sub-assembly (mode damper servo)
  • Air conditioning harness assembly
  • No. 1 air conditioning amplifier assembly
WIRING DIAGRAM
PROCEDURE
  1. READ VALUE USING TECHSTREAM (MODE DAMPER SERVO)

(a) Use the Data List to check if the damper servo sub-assembly (mode damper servo) is functioning properly (See page ).


Air Conditioner

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Air Outlet Servo Pulse (D)

Damper servo sub-assembly (mode damper servo) actual pulse / Min.: 0, Max.: 255

15 (pulse): FACE 1

15 (pulse): FACE 2

41 (pulse): B/L

65 or 73 (pulse): FOOT

83 or 95 (pulse): F/D

113 (pulse): DEF

-

Air Outlet Servo Actu Pulse (D)

Damper servo sub-assembly (mode damper servo) actual pulse / Min.: 0, Max.: 255

15 (pulse): FACE 1

15 (pulse): FACE 2

41 (pulse): B/L

65 or 73 (pulse): FOOT

83 or 95 (pulse): F/D

113 (pulse): DEF

-

OK:

The display is as specified in the normal condition column.

Result

Result

Proceed to

OK (When troubleshooting according to problem symptoms table)

A

OK (When troubleshooting according to the DTC)

B

NG

C


A

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE


B

REPLACE NO. 1 AIR CONDITIONING AMPLIFIER ASSEMBLY

C
  1. PERFORM ACTIVE TEST USING TECHSTREAM (MODE DAMPER SERVO)

(a) Select the Active Test, use the Techstream to generate a control command, and then check that the damper servo sub-assembly (mode damper servo) operates (See page ).


Air Conditioner

Tester Display

Test Part

Control Range

Diagnostic Note

Air Outlet Servo Pulse (D)

Damper servo sub-assembly (mode damper servo) pulse

Min.: 0, Max.: 255

-

OK:

Damper servo sub-assembly (mode damper servo) operates normally.


OK

REPLACE NO. 1 AIR CONDITIONING AMPLIFIER ASSEMBLY

NG
  1. REPLACE DAMPER SERVO SUB-ASSEMBLY (MODE DAMPER SERVO)

(a) Replace the damper servo sub-assembly (mode damper servo) (See page ).


HINT:

Since the damper servo sub-assembly (mode damper servo) cannot be inspected while it is removed from the vehicle, replace the damper servo sub-assembly (mode damper servo) with a new or normally functioning one.

NEXT
  1. CHECK FOR DTC

(a) Clear the DTCs (See page ).


(b) Check for DTCs (See page ).


OK:

DTC B1443 is not output.


OK

END (DAMPER SERVO SUB-ASSEMBLY [MODE DAMPER SERVO] IS FAULTY)

NG
  1. REPLACE NO. 1 AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Temporarily replace the No. 1 air conditioning amplifier assembly with a new or normally functioning one (See page ).


NEXT
  1. CHECK FOR DTC

(a) Clear the DTCs (See page ).


(b) Check for DTCs (See page ).


OK:

DTC B1443 is not output.


OK

END (NO. 1 AIR CONDITIONING AMPLIFIER ASSEMBLY IS FAULTY)


NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY

Test yourself

A quick Toyota 4Runner quiz: every answer comes with an explanation and a link to the manual page.