B1446

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

DESCRIPTION

The air mix control servo motor sends pulse signals to indicate the damper position to the A/C amplifier. The A/C amplifier activates the motor (normal or reverse) based on these signals to move the air mix damper (driver side) to any position. As a result, the amount of air passing through the heater core after passing through the evaporator is adjusted, and the temperature of the air blowing toward the driver side is controlled.

The A/C 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 stored when either a damper link or the damper is mechanically locked.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

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

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

Air Conditioner





OK:

The display is as specified in the normal condition column.

Result:





C -- REPLACE A/C AMPLIFIER Removal

B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures
A -- Continue to next step.

2. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(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





OK:

Air temperature changes in accordance with each control range.

NG -- INSPECT AIR MIX CONTROL SERVO MOTOR

OK -- REPLACE A/C AMPLIFIER Removal

3. INSPECT AIR MIX CONTROL SERVO MOTOR

(a) Replace the air mix control servo motor Disassembly.

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

(b) Check for the DTC.

Result:





B -- END (AIR MIX CONTROL SERVO MOTOR WAS DEFECTIVE) Disassembly
A -- Continue to next step.

4. INSPECT AIR CONDITIONING HARNESS

(a) Replace the air conditioning harness Disassembly.

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

(b) Check for the DTC.

Result:





B -- END (AIR CONDITIONING HARNESS WAS DEFECTIVE) Disassembly

A -- REPLACE A/C AMPLIFIER Removal