B1446

AIR CONDITIONING SYSTEM: B1446/46: Air Mix Damper Control Servo Motor Circuit (Driver Side)

DTC B1446/46 - Air Mix Damper Control Servo Motor Circuit (Driver Side)

DESCRIPTION

The air mix control servo motor is controlled by the A/C amplifier.
The air mix control servo motor moves the air mix damper by rotating (normal, reverse) the motor with electrical power from the A/C amplifier.
This adjusts the mix ratio of the air that passes through the evaporator and heater core and controls the air flow 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 INTELLIGENT TESTER
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the intelligent tester main switch on.
(c) Select the item below in the DATA LIST, and read the display on the intelligent tester.

DATA LIST / AIR CONDITIONER:





OK:
When the target position is at the "MAX. COOL" (-5%), the actual opening angle is 19.0% or less.
When the target position is at the "MAX. HOT" (105%), 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.
2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the intelligent tester main switch on.
(c) Select the item below in the ACTIVE TEST and then check the air flow temperature by hand.

ACTIVE TEST / AIR CONDITIONER:





OK:
When the lever is moved to the "MAX. HOT" side, warm air comes out.
When the lever is moved to the "MAX. COOL" side, cool air comes out.
Result:






C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.
3. PERFORM ACTUATOR CHECK
(a) Set the actuator check mode .
(b) Press the DEF switch and change to the step operation.
(c) Check the air flow temperature by hand.






OK:
Air flow temperature changes in accordance with each display code.
Result:






C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.
4. INSPECT AIR MIX CONTROL SERVO MOTOR





(a) Remove the air mix control servo motor.
(b) Disconnect the connector from the air mix control servo motor.
(c) Connect the positive (+) lead from the battery to terminal 5 and the negative (-) lead to terminal 4, then check that the lever turns to the "MAX. HOT" position smoothly.
OK:
Lever turns to "MAX. HOT" position smoothly.
(d) Connect the positive (+) lead from the battery to terminal 4 and the negative (-) lead to terminal 5, then check that the lever turns to the "MAX. COOL" position smoothly.
OK:
Lever turns to "MAX. COOL" position smoothly.
NG -- REPLACE AIR MIX CONTROL SERVO MOTOR
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (AIR MIX CONTROL SERVO MOTOR - A/C AMPLIFIER)





(a) Disconnect the connector from the A/C amplifier.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






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