Low Pressure Sensor Circuit

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: Low Pressure Sensor Circuit
- Low Pressure Sensor Circuit

DESCRIPTION

The low pressure sensor reduces the capacity of the compressor when the compressor is operating at high speed. This sensor monitors the pressure on the low pressure side at terminal CUT+ and sends a signal to terminal PSW of the A/C amplifier, which increases the accuracy of compressor control.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK REFRIGERANT PRESSURE

(a) Check the sight glass of the cooler unit refrigerant liquid pipe.





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





(2) Compare the sight glass to the following chart.





*: Bubbles in the sight glass with the vehicle interior temperature above 35°C (95°F) can be considered normal if cooling is sufficient.
NG -- CHARGE REFRIGERANT Service and Repair
OK -- Continue to next step.

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

(a) Disconnect the pressure sensor connector.





(b) Disconnect the A/C amplifier connector.

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

Standard Resistance:





Text in Illustration





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

3. REPLACE LOW PRESSURE SENSOR

(a) Replace the low pressure sensor with a normal one Removal and check that the condition returns to normal.

OK:

Same problem does not occur.

NG -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

OK -- END (LOW PRESSURE SENSOR WAS DEFECTIVE)