Diagnosis And Testing - A/C Pressure Transducer

WARNING: This page is about a different variant/trim than selected.

Before testing the A/C pressure transducer, be certain that the transducer wire harness connection is clean of corrosion and properly connected. For the A/C to operate, an A/C pressure transducer voltage reading between 0.451 and 4.519 volts is required. Voltages outside this range indicate a low or high refrigerant system pressure condition to the Electric Vehicle Control Unit (EVCU). The EVCU is programmed to respond to a low or high refrigerant system pressure by suppressing operation of the A/C compressor. Refer to A/C PRESSURE TRANSDUCER VOLTAGE for the possible conditions indicated by the transducer voltage reading.

NOTE:

If the A/C compressor remains engaged regardless of the actual pressure and the measured A/C sensor voltage is within the range of 3.360-3.375 V, then check the A/C pressure transducer return circuit for an open condition. A long term open A/C pressure transducer open return circuit, may result in a release of the refrigerant and oil through the pressure relief valve.

The A/C pressure transducer is tested using a scan tool. Refer to DIAGNOSIS AND TESTING .

A/C PRESSURE TRANSDUCER VOLTAGE

Voltage	Possible Indication
0.0	1. No sensor supply voltage from EVCU.
	2. Shorted sensor circuit.
	3. Inoperative transducer.
0.150 TO 0.450	1. Ambient temperature below 10° C (50° F).
	2. Low refrigerant system pressure.
3.360 TO 3.375	1. Sensor ground pin open circuit (A/C runs regardless of actual pressure).
0.451 TO 4.519	1. Normal refrigerant system pressure.
4.520 TO 4.850	1. High refrigerant system pressure.
5.0	1. Open sensor circuit.
	2. Inoperative transducer.