Pressure Sensor Circuit - Air Conditioning System

AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1423/23: Pressure Sensor Circuit
B1423/23 - Pressure Sensor Circuit

DESCRIPTION

This DTC is output when refrigerant pressure is 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 pressure sensor, which is installed on the pipe of the high pressure side to detect refrigerant pressure, outputs the refrigerant pressure signal to the air conditioning amplifier. The air conditioning amplifier converts the signals into pressure according to the sensor characteristics to control the compressor.

HINT
Be sure to check the refrigerant volume first when this DTC is output because this DTC can also be output if there is no refrigerant in the cycle.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT REFRIGERANT PRESSURE

(a) Set the manifold gauge Refrigerant.

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





(1) Prepare the vehicle according to the chart below.





Standard:

Low pressure side
0.15 to 0.25 MPa (1.5 to 2.5 kgf/cm2, 21.3 to 35.6 psi)

High pressure side
1.37 to 1.57 MPa (14 to 16 kgf/cm2, 199 to 228 psi)

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

2. READ VALUE USING TECHSTREAM

(a) Connect Techstream to DTC3.

(b) Turn the ignition switch on (IG) and turn Techstream on.

(c) Select the items below in the Data List, and read the displays on Techstream.

Data List / Air Conditioner:





OK:

The display 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.

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

(a) Disconnect the connector from A/C amplifier.

(b) Disconnect the connector from the A/C pressure sensor.

(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 (S5-2 - SG-2)

(a) Remove the A/C amplifier.

(b) Reconnect the connector to the A/C amplifier.





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

Standard Voltage:





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

5. INSPECT A/C PRESSURE SENSOR

(a) Start the engine.





(b) Operate the air conditioning system.

(c) Disconnect the connector from A/C pressure sensor.

(d) Install the manifold gauge set Refrigerant.

(e) Connect the positive (+) lead from the three 1.5 V dry cell batteries to terminal A35-3 and negative (-) lead to terminal A35-1.

(f) Check the voltage between terminals A35-2 and A35-1 of A/C pressure sensor.

Voltage:

The voltage depends on the refrigerant pressure as shown in the chart.

NG -- REPLACE A/C PRESSURE SENSOR

OK -- REPLACE AIR CONDITIONING AMPLIFIER