Circuit Description
The A/C refrigerant pressure sensor responds to the changes in the A/C refrigerant high side pressure. This input indicates how much load the A/C compressor is putting on the engine and is one of the factors used by the Powertrain Control Module (PCM) in order to determine the Idle Air Control (IAC) position for the idle speed. The circuits consist of a 5 V 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. The sensor's operating range is between 0 and 459 psi. At 0 psi, the signal voltage will be about 0.1 V, varying to about 4.9 V at 459 psi.
Conditions for Running The DTC
The A/C refrigerant sensor pressure is more than 453 psi (4.92 V) with the A/C requested.
OR
The A/C refrigerant sensor pressure is more than 363 psi (3.98 V) with the A/C not requested
OR
The A/C refrigerant pressure sensor is less than 0 psi (0.10V) 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 V) 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 will record the operating conditions at the time during which the diagnostic fails. This information will store in the Failure Records buffer. |
| • | A history DTC stores. |
| • | The PCM will disable the A/C compressor clutch. |
Conditions for Clearing the MIL/DTC
| • | A history DTC will clear after 40 consecutive warm up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
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. |
| • | 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.
-
If the MAP or TP sensor DTC is set, the malfunctioning circuit is diagnosed in these tables.
-
Determines if the low voltage signal was from the sensor or the signal circuit. Jumping the signal circuit to the 5 volt reference checks the circuits, connections and the PCM.
-
The replacement PCM must be programmed and the crankshaft position system variation procedure must be preformed. Refer to the latest Techline procedure for PCM reprogramming.
-
If no malfunctions have been found at this point and no additional DTCs were set, refer to Diagnostic Aids for additional checks and information.
Step | Action | Values) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | |||||||
Were any MAP or TP DTCs also set? | -- | Go to MAP or TP DTC Tables | ||||||
3 | Does the A/C high side value read greater than the specified value? | 4.0 V (363 psi) | ||||||
4 | Disconnect the A/C pressure sensor electrical connector. Is the A/C high side value less than the specified value? | 1.0 V (76 psi) | ||||||
5 | Is the A/C high side value less than the specified value? | 0.20 V (0 psi) | ||||||
6 |
Does the test lamp illuminate? | -- | ||||||
7 |
Does the DMM measure near the specified voltage? | 5.0 V | ||||||
8 |
Does the A/C compressor clutch remain engaged? | -- | ||||||
9 |
Is the action complete? | -- | -- | |||||
10 |
Was a repair necessary? | -- | ||||||
11 | Connect a DMM to ground and probe the A/C Refrigerant Pressure sensor signal circuit. Is the voltage between the specified values? | 4.0-6.0 V | ||||||
Connect a jumper wire to the following A/C Refrigerant Pressure sensor electrical connectors:
Does the scan tool A/C High side value read greater than the specified value? | 4.6 V (421 psi) | |||||||
13 |
Important: The Powertrain Control Module (PCM) uses a single internal 5.0 volt power supply to supply power to all the engine control components. If one component shorts its 5.0 volt reference circuit go ground or battery voltage, the other 5.0 volt reference circuits will also have a low or high voltage. Repair the open, short to ground, or poor connection in the A/C refrigerant pressure sensor 5 volt reference circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |||||
14 |
Does the test lamp illuminate? | -- | ||||||
Important : The PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Did you complete the repair? | -- | -- | ||||||
16 |
Was a repair necessary? | -- | ||||||
17 |
Was a repair necessary? | -- | ||||||
18 |
Does the test lamp illuminate? | 0.5 V | ||||||
19 |
Was a repair necessary? | -- | ||||||
20 | Did the A/C clutch disengage when the relay was removed? | -- | ||||||
21 |
Was a repair necessary? | -- | ||||||
22 |
Was a repair necessary? | -- | ||||||
23 | Replace the A/C compressor clutch relay. Refer to Air Conditioning (A/C) Compressor and Cooling Fan Relays Replacement Is the action complete? | -- | -- | |||||
24 |
Was a repair necessary? | -- | ||||||
25 | Replace a malfunctioning A/C compressor clutch. Refer to Air Conditioning Compressor Replacement in Heating, Ventilation, and Air Conditioning. Is the action complete? | -- | -- | |||||
26 |
Does the scan tool indicate that this diagnostic has ran and passed? | -- | ||||||
Check if any additional DTCs are set. Are any DTCs displayed that has not been diagnosed? | -- | Go to applicable DTC table | System OK |
