P1530

DTC P1530:

A/C Refrigerant Pressure Sensor & Compressor Wiring Schematic:

CIRCUIT DESCRIPTION
The A/C refrigerant pressure sensor is located in the high side of the A/C cooling system and signals the Powertrain Control Module (PCM) of refrigerant pressure changes. This input indicates how much load the A/C compressor is putting on the engine. The PCM uses this input to determine Idle Air Control (IAC) valve position for idle speed control. This 3 wire sensor has a 5 volt reference input, a signal line and a ground.
When pressure is low, a low signal voltage is sensed at the PCM. As pressure rises, the voltage increases at PCM terminal "BB12" which is translated by the PCM into rising pressure. If the signal voltage remains below a calibrated value, a Diagnostic Trouble Code P1530 is set which indicates a sensor or circuit failure.

DIAGNOSTIC TROUBLE CODE (DTC) P1530 WILL SET WHEN
The signal voltage sensed at terminal "BB12" is below 0.1 volt for 25.4 seconds when A/C is selected "ON" and the engine is running or signal voltage sensor sensed at terminal "BB12" is above 4.92 volts for 25.4 seconds when A/C is selected "ON" and the engine is running.

ACTION TAKEN (PCM WILL DEFAULT TO)
The Malfunction Indicator Lamp (MIL) will not become illuminated but the A/C compressor will be disabled.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This step checks the voltage signal being received by the PCM from the A/C pressure sensor.
2. Checks to see if low voltage signal is from the sensor or the circuit. Jumpering the sensor signal CKT 380 to 5 volts checks the circuit, connections, and PCM.
3. This step checks to see if the low signal voltage was due to an open in the sensor circuit or the 5 volts reference circuit since the previous step eliminated the pressure sensor.
4. Checks to see if the high voltage signal is from a shorted sensor or a short to voltage in CKT 380 or ground CKT 452 open. Normally, disconnecting the sensor would make a normal circuit go to near zero volts.

DIAGNOSTIC AIDS
DTC P1530 sets when signal voltage falls outside the normal possible range of the sensor and is not due to a refrigerant system problem. If the problem is intermittent, check for opens or shorts in harness or poor connections.