B1432

AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1432: Air Inlet Damper Position Sensor Circuit

DTC B1432 - Air Inlet Damper Position Sensor Circuit

DESCRIPTION

This sensor detects the position of the air inlet control servo motor and sends the appropriate signals to the air conditioning amplifier. The position sensor is built into the air inlet control servo motor.
The position sensor's resistance changes as the air inlet control servo motor arm moves.
It outputs voltage (5 V) that is input to terminal 3 (VZ) and terminal 3 (PT) via the variable resistor, and then to the air conditioning amplifier. The air conditioning amplifier reads the arm position with the input voltage from the position sensor.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM
(a) Connect Techstream to DLC3.
(b) Turn the power switch ON (IG) and turn Techstream ON.
(c) Select the item below in the Data List, and read the display on Techstream.

Air conditioning amplifier

OK:
The displayed is as specified in the normal condition.

Result

C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.

2. CHECK AIR CONDITIONING AMPLIFIER (TPI VOLTAGE)

(a) Remove the air conditioning amplifier with connectors still connected.
(b) Change the set REC / FRS to activate the air inlet servo motor.
(c) Measure the voltage of the wire harness side connector.
Standard voltage:

HINT: As the air inlet servo motor is moved from REC position to FRS position, the voltage decreases gradually without interruption.

Result:

C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.

3. INSPECT AIR INLET CONTROL SERVO MOTOR

(a) Remove the air inlet control servo motor.
(b) Measure the resistance of the servo motor.
Standard resistance:

HINT:
- Refer to the operation procedure of the air inlet control servo motor B1442.
- As the air inlet control servo motor moves from FRESH position to RECIRCULATION position, the resistance decreases gradually without interruption.

NG -- REPLACE AIR INLET CONTROL SERVO MOTOR
OK -- Continue to next step.

4. CHECK WIRE HARNESS (AIR INLET CONTROL SERVO MOTOR - AIR CONDITIONING AMPLIFIER)

(a) Disconnect the A14 servo connector.
(b) Disconnect the A7 amplifier connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:

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