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 damper servo sends pulse signals to inform the A/C amplifier of the damper position. The A/C amplifier activates the motor (normal, reverse) based on the signals to move the air mix damper (driver seat) 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 seat 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 diagnostic code can be output 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) Operate the driver side temperature adjustment switch.

(e) Select the item below in the Data List, and read the display on the Techstream.

Data List / Air Conditioner





OK:

The display is as specified in the normal condition column.

Result:





C -- REPLACE A/C AMPLIFIER Removal

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

2. 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 -- REPLACE AIR MIX CONTROL SERVO MOTOR Disassembly
A -- Continue to next step.

3. 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 -- REPLACE AIR CONDITIONING HARNESS Disassembly

A -- REPLACE A/C AMPLIFIER Removal