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. The circuits consist of a 5V reference and a ground, both provided by the ECM and a signal from 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 4.65V lasts for more than 10 sec., ECM sets P0533.
DTC Detecting Condition
Specification
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
Fig.2) Normal data of A/C pressure sensor without A/C switch ON.
Fig.3) Abnormal data of A/C pressure sensor when A/C pressure sensor circuit open.