Air Conditioning System (For Manual Air Conditioning System)

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Manual Air Conditioning System): B1423: Pressure Sensor Circuit
B1423 - Pressure Sensor Circuit

DESCRIPTION

This DTC is output when the refrigerant pressure is either extremely low (0.19 MPa [2.0 kgf/cm2, 28 psi] or less) or extremely high (3.14 MPa [32.0 kgf/cm2, 455 psi] or more). The air conditioner pressure sensor, which is installed on the pipe of the high pressure side, detects the refrigerant pressure and sends refrigerant pressure signals to the air conditioning amplifier. The air conditioning amplifier determines the pressure from the signals in accordance with the sensor characteristics, and controls the compressor accordingly.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK REFRIGERANT PRESSURE





(a) Install the manifold gauge set Refrigerant.

(b) Read the manifold gauge pressure when the following conditions are established.

(1) Prepare the vehicle in accordance with the chart below.





(2) When the refrigerant volume is correct, the gauge reading indicates as follows:

Standard:





HINT
Pressure varies in accordance with certain conditions such as outside air temperature, sunlight and wind.

NG -- CHARGE REFRIGERANT Refrigerant
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (REG PRESS SENS)

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(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 AIR CONDITIONING AMPLIFIER Removal

B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Air Conditioning System (for Manual Air Conditioning System)
A -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER)

(a) Disconnect the air conditioner pressure sensor connector.

(b) Disconnect the air conditioning amplifier connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. INSPECT AIR CONDITIONING AMPLIFIER

(a) Remove the air conditioning amplifier with its connectors still connected.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





(c) Turn the ignition switch to ON.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPLACE AIR CONDITIONING AMPLIFIER Removal
OK -- Continue to next step.

5. INSPECT AIR CONDITIONER PRESSURE SENSOR

(a) Remove the air conditioning amplifier with its connectors still connected.





(b) Set the manifold gauge.

(c) Warm up the engine.

(d) Turn the A/C switch ON.

(e) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





NG -- REPLACE AIR CONDITIONER PRESSURE SENSOR Removal

OK -- REPLACE AIR CONDITIONING AMPLIFIER Removal