With Automatic Climate Control

TROUBLE DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR

Symptom:
- Air mix door does not operate normally.

Inspection Flow:

CONTROL SYSTEM OUTPUT COMPONENTS

Air Mix Door Control (Automatic Temperature Control)

Component Parts
Air mix door control system components are:

1. EATC unit
2. Air mix door motor
3. PBR
4. In-vehicle temperature sensor
5. Ambient temperature sensor
6. Sunload sensor





System Operation
Temperature set by temperature control switch is compensated through setting temperature correction circuit to determine target temperature.

EATC unit will operate air mix door motor to set air conditioning system in WARM or COOL position, depending upon relationship between conditions (target temperature, sunload, in-vehicle temperature and ambient temperature) and conditions (air mix door position and compressor operation).

Air Mix Door Control Specification:

Air Mix Door Motor
The air mix door motor is attached to the bottom of the heater unit. It rotates so that the air mix door is opened to a position set by the EATC unit. Motor rotation is then conveyed through a rod and air mix door position is then fed back to the EATC unit by PBR built-in air mix door motor.





PBR Characteristics
Measure resistance between terminals 3 and 4 at vehicle harness side.
























AIR MIX DOOR MOTOR CIRCUIT (EATC SELF-DIAGNOSIS CODE 20, 22, OR 28)

SYMPTOM:
- Air mix door does not operate normally. (20, & 22, or 28 is indicated on the EATC unit as a result of conducting Self-diagnosis).








AIR MIX DOOR MOTOR CIRCUIT (EATC SELF-DIAGNOSIS CODE 26 & OR 27)

SYMPTOM:
- Air mix door motor PBR circuit is open or shorted. (26 or 27 is indicated on the EATC unit as a result of conducting Self-diagnosis).





CONTROL LINKAGE ADJUSTMENT

Air Mix Door
Before adjusting, push temperature control rod fully forward to front of vehicle. Note position of clasp.

1. Install air mix door motor on heater unit and connect it to the air mix door motor harness.
2. Turn ignition switch ON.
3. Press the temperature control switch until 16 °C (60 °F) is displayed.
4. Move the air mix door by hand to maximum cold position (door completely covers heater core) and hold it.
5. While holding the air mix door, adjust the length of temperature control rod and connect it to the air mix door lever.
6. Check that air mix door operates properly when temperature control switch is set from 16 to 32 °C (60 to 90 °F).