B1441

AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1441: Air Mix Damper Control Servo Motor Circuit (Passenger Side)

DTC B1441 - Air Mix Damper Control Servo Motor Circuit (Passenger Side)

DESCRIPTION

The air mix control servo motor (air mix damper servo) is controlled by the air conditioning amplifier.
The air mix control servo motor moves the air mix damper by rotating (normal, reverse) the motor with electrical power from the air conditioning amplifier.
This adjusts the mix ratio of the air that passes through the evaporator and heater core and controls the airflow temperature. Air flow temperature changes when moving the air mix damper to the target point. The target point can be detected with the air mix damper position sensor.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM
(a) Connect Techstream to DLC3.
(b) Turn the power switch ON (IG) and turn Techstream ON.
(c) Select the item below in the Data List, and read the display on Techstream.

Air conditioning amplifier





OK:
When the target position is at the "MAX. COOL" (-10.0%), the actual opening angle is 19.0% or less.

Result





C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.

2. READ VALUE USING TECHSTREAM
(a) Connect Techstream to DLC3.
(b) Turn the power switch ON (IG) and turn Techstream ON.
(c) Select the item below in the Data List, and read the display on Techstream.

Air conditioning amplifier





OK:
When the target position is at the "MAX. HOT" (100.0%), the actual opening angle is 81.0% or more.

Result





C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.

3. INSPECT AIR MIX CONTROL SERVO MOTOR




(a) Remove the air mix control servo motor.
(b) Connect the battery's positive (+) lead to terminal 5 and negative (-) lead to terminal 4, then check that lever turns to "MAX. HOT" position smoothly.
(c) Measure the resistance of the servo motor.
Standard resistance:





(d) Connect the battery's positive (+) lead to terminal 4 and negative (-) lead to terminal 5, then check that lever turns to "MAX. COOL" position smoothly.
(e) Measure the resistance of the servo motor.
Standard resistance:






NG -- REPLACE AIR MIX CONTROL SERVO MOTOR
OK -- Continue to next step.

4. CHECK WIRE HARNESS (AIR MIX CONTROL SERVO MOTOR - AIR CONDITIONING AMPLIFIER)




(a) Disconnect the A15 servo connector.
(b) Disconnect the A8 amplifier connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- REPLACE AIR CONDITIONING AMPLIFIER