P0533

Circuit Description

The A/C Refrigerant Pressure sensor is a sensor that changes resistance based upon refrigerant pressure. The PCM provides a 5 volt reference and ground. The A/C refrigerant sensor signal varies between ground and 5 volts as refrigerant pressure varies. As A/C refrigerant pressure increases, voltage increases. As A/C refrigerant pressure decreases, voltage decreases. If the A/C pressure sensor signal goes high such as when the signal line is shorted to voltage or the A/C pressure sensor is shorted internally, DTC P0533 will set.

Conditions for Running the DTC

Engine running.

Conditions for Setting the DTC

The A/C refrigerant pressure sensor reading has been 5.00 volts or higher.

Action Taken When the DTC Sets

^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ No message will be displayed.

Conditions for Clearing the MIL/DTC

^ A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
^ A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
^ Use a scan tool to clear DTCs.
^ Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes. Reading and Clearing Diagnostic Trouble Codes

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

2. If the A/C refrigerant pressure sensor value is greater than 5.0 volts, a A/C refrigerant pressure sensor circuit problem must be present.
3. If A/C refrigerant pressure value is less than 0.10 volts, the fault is the A/C refrigerant pressure sensor or the reference voltage is higher than 5.06 volts.
7. A high voltage reading on the 5 volt reference circuit could be caused by a short to voltage on another 5 volt reference circuit, some 5V Ref. circuits are shared inside the PCM, or battery voltage bleeding onto the 5 volt reference circuit as in a defective Linear EGR Valve.