General Information

Component Location





General Description

The ECM (Engine Control Module) receives pressure signal in the A/C refrigerant high pressure side from the A/C refrigerant pressure sensor. This input indicates how much load the A/C compressor is putting on the engine and is one of the factors used by the ECM in order to determine the idle air control position for the idle speed. Along with the sensor signal wire, the ECM supplies both a 5V reference and a ground to the sensor. The signal is a voltage which is proportional to the A/C pressure from 0 to 5V. Low pressure produces a low voltage signal and high pressure a high-voltage signal.

DTC Description

Checking output signals from A/C pressure sensor under detecting condition, if an signal above 4.668V lasts for more than 10 sec., ECM sets P0533.

DTC Detecting Condition





Diagnostic Circuit Diagram





Signal Waveform & Data




Fig. 1) Normal waveforms of A/C pressure sensor during the time from turning on A/C switch to turning off A/C switch