Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM10000000102CI
Model Year Start: 2017 Model: Sienna Prod Date Range: [08/2016 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1443/43; Air Outlet Damper Control Servo Motor Circuit; 2017 - 2020 MY Sienna [08/2016 -        ]

DTC

B1443/43

Air Outlet Damper Control Servo Motor Circuit

DESCRIPTION

The air outlet control servo motor sends pulse signals to indicate the damper position to the air conditioning amplifier. The air conditioning amplifier activates the motor (normal or reverse) based on these signals to move the mode damper to any position, which controls the air outlet switching.

The air conditioning amplifier communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness.

HINT:

Confirm that no mechanical problem is present because this DTC can be output when either a damper link or the damper is mechanically locked.

DTC Code

DTC Detection Condition

Trouble Area

B1443/43

Air outlet damper position sensor value does not change even if air conditioning amplifier operates air outlet control servo motor

  • Air outlet control servo motor
  • Air conditioning harness
  • Air conditioning amplifier

WIRING DIAGRAM

PROCEDURE

1.

READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Operate the MODE switch.

(e) Enter the following menus: Body Electrical / Air Conditioner / Data List.

(f) Check the value(s) by referring to the table below.

Air Conditioner

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Air Outlet Servo Pulse (D)

Air outlet servo motor target pulse /

Min.: 128

Max.: 383

FACE: 136 (pulse)

B/L: 158 to 166 (pulse)

FOOT: 178 to 202 (pulse)

FOOT/DEF: 208 (pulse)

DEF: 225 (pulse)

-

OK:

The display is as specified in the Normal Condition column.

Result

Result

Proceed to

NG

A

OK (When troubleshooting according to Problem Symptoms Table)

B

OK (When troubleshooting according to the DTC)

C

B

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

C

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

A

2.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(e) Check the operation by referring to the table below.

Air Conditioner

Tester Display

Test Part

Control Rage

Diagnostic Note

Air Outlet Servo Pulse (D)

Air outlet servo motor pulse

Min.: 128, Max.: 383

-

OK:

Air flow position changes in accordance with each control range.

OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

3.

INSPECT AIR INLET SERVO MOTOR

(a) Replace the No. 1 air mix control servo motor (air outlet control servo motor) (See page 2017 - 2020 MY Sienna [08/2016 -        ]; HEATING / AIR CONDITIONING: FRONT AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1443/43 is output

A

DTC B1443/43 is not output

B

B

REPLACE AIR INLET SERVO MOTOR

A

4.

INSPECT AIR CONDITIONING HARNESS

(a) Replace the air conditioning harness (See page 2017 - 2020 MY Sienna [08/2016 -        ]; HEATING / AIR CONDITIONING: FRONT AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the air conditioning harness cannot be inspected while it is removed from the vehicle, replace the air conditioning harness with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1443/43 is output

A

DTC B1443/43 is not output

B

A

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

B

REPLACE AIR CONDITIONING HARNESS