Air Outlet Damper Control Servo Motor Circuit (B1443/43)
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). |
|
PROCEDURE
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.
ResultResult | 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 |
|
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 |
|
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.
|
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) |
|
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
).
|
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.
.gif)
.gif)