Circuit Description
The A/C refrigerant pressure sensor responds to changes in A/C refrigerant high side pressure. This input indicates how much load the A/C compressor is putting on the engine. The powertrain control module (PCM) uses this input in order to determine the idle air control (IAC) position for idle speed. The PCM supplies the A/C refrigerant pressure sensor with a 5V reference and a ground circuit. A signal voltage is sent back to the PCM by the A/C refrigerant pressure sensor which is proportional to the A/C pressure. The operating range of the sensor is between 0 and 459 psi. At 0 psi the signal voltage will read between 0.20 volts varying to 5.0 volts at 459 psi or above.
Conditions for Running The DTC
The A/C refrigerant sensor pressure is more than 453 psi (4.90 volt) with the A/C requested.
OR
The A/C refrigerant sensor pressure is more than 363 psi (4.0 volt) with the A/C not requested.
OR
The A/C refrigerant pressure sensor is less than 0 psi (0.10 volt) when the intake air temperature is more than 0°C (32°F) and DTC P0112 or P0113 is not set.
OR
The A/C refrigerant sensor pressure is less than 0 psi (0.10 volt) when an IAT sensor DTC is present.
Conditions for Setting the DTC
Any of the above conditions are met for 15 seconds.
Action Taken When the DTC Sets
| • | The PCM records the operating conditions at the time the diagnostic fails. The Failure Records buffers stores this information. |
| • | The PCM stores a history DTC. |
| • | The PCM disables the A/C compressor clutch. |
Conditions for Clearing the DTC
| • | A history DTC clears after 40 consecutive warm up cycles without a fault. |
| • | The scan tool can clear the DTC. |
Diagnostic Aids
| • | The DTC P0530 sets when the signal voltage falls outside of the normal possible range of the sensor. |
| • | If the actual pressure of the A/C system matches the scan tool readings, repair any A/C pressure problems before using this table. Refer to the Air Conditioning System section of the service manual. |
| • | Thoroughly check any suspected circuitry for the following conditions: |
| - | Backed out terminals |
| - | Improper mating of the terminals |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Poor terminal to wiring connections |
| - | Physical damage to the wiring harness |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
The Powertrain OBD System Check prompts the technician to complete some basic checks and store the Freeze Frame and Failure Records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
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This step determines if the fault is present or is an intermittent fault.
-
This step determines if the fault is an electrical fault or a refrigerant pressure fault.
-
The replacement PCM must be programmed and the Crankshaft Position System Variation Learn Procedure must be performed.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | |||
Does the A/C pressure sensor value read within the specified values? | 0-450 psi | |||
3 |
Does the DTC reset? | -- | Go to Diagnostic Aids | |
4 | Are any MAP or TP codes set? | -- | Go to Applicable DTC | |
Does the A/C gauge and the scan tool read within the specified value of each other? | 20 psi | Go to System Performance Test in Heating, Ventilation and Air Conditioning | ||
6 | With the scan tool, observe the A/C pressure reading. Does the A/C pressure sensor read the specified value or less? | 0 psi | ||
7 |
Does the A/C pressure read less than the specified value? | 76 psi | ||
8 |
Does the A/C pressure sensor read near the specified value? | 450 psi | ||
9 |
Does the A/C pressure sensor read near the specified value? | 5 V | ||
10 | Test the A/C pressure sensor 5 volt reference for an open or short to ground. Did you find a condition? | -- | ||
11 | Test/inspect the A/C pressure sensor ground circuit for an open or poor connection. Did you find a condition? | -- | ||
12 | Test the A/C pressure sensor signal circuit for an open or short to ground. Did you find a condition? | -- | ||
13 | Test the A/C pressure sensor signal circuit for a short to voltage. Did you find a condition? | -- | ||
14 | Repair as necessary. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
15 |
Did you find and repair the condition? | -- | ||
16 | Replace the A/C pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | -- | -- | |
|
Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | -- | ||
18 |
Does the DTC reset? | -- | System OK |
