The PCM(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 PCM 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 PCM, 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.
PCM sets DTC P0553 if the PCM detects signal higher than the possible range of a properly operating sensor.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Electrical Check | 1. Short to power in signal circuit 2. Open in ground circuit 3. Poor connection or damaged harness 4. Faulty A/C pressure sensor |
Enable Conditions |
•
10V < Battery voltage < 16V | |
Threshold value |
•
Signal voltage > 4.7V | |
Diagnosis Time |
•
30 Seconds | |
MIL On Condition |
•
- |
