B1442

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1442/42: Air Inlet Damper Control Servo Motor Circuit
B1442/42 - Air Inlet Damper Control Servo Motor Circuit

DESCRIPTION

The damper servo (air inlet control) 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 inlet mode selection air inlet control damper to any position, which controls the intake air settings (FRESH, FRESH/RECIRCULATION, and RECIRCULATION).

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 R/F (Recirculation/Fresh) 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 INLET CONTROL SERVO MOTOR

(a) Replace the air inlet 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 INLET 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