Air Conditioning System (For Manual Air Conditioning System)

AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Manual Air Conditioning System): B1423/23: Pressure Sensor Circuit
B1423/23 - Pressure Sensor Circuit

DESCRIPTION

This DTC is output when refrigerant pressure is extremely low (196 kPa (2.0 kgf/cm2, 28 psi) or less) or extremely high (3140 kPa (32.0 kgf/cm2, 455 psi) or more). The pressure switch, which is installed on the pipe of the high pressure side to detect refrigerant pressure, outputs a refrigerant pressure signal to the air conditioning amplifier.

The air conditioning amplifier controls the compressor according to the sensor characteristic.

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 system.





WIRING DIAGRAM





INSPECTION PROCEDURE

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 system.

PROCEDURE

1. CHECK HARNESS OR CONNECTOR (A/C PRESSURE SWITCH - A/C AMPLIFIER AND BODY GROUND)





(a) Disconnect the A20 air conditioning pressure switch connector.

(b) Disconnect the J19 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.

2. CHECK AIR CONDITIONING PRESSURE SWITCH

(a) Set the manifold gauge set.





(b) Disconnect the air conditioning pressure switch connector.

(c) Run the engine at approximately 2000 rpm.

(d) Set the blower speed control switch to the HI position.

(e) Set the temperature control level to the MAX. COOL position.

(f) Turn the A/C switch ON.

(g) Check the switch operation.

(1) Connect the positive (+) lead from an ohmmeter to terminal 1 and the negative (-) lead to terminal 2.

(2) Measure the resistance between the terminals when refrigerant pressure is changed, as shown in the illustration.





OK:

Resistance varies as shown in the illustration.

Result





C -- REPLACE AIR CONDITIONING AMPLIFIER Removal

B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Air Conditioning System (for Manual Air Conditioning System)

A -- REPLACE AIR CONDITIONING PRESSURE SWITCH Removal