The engine control module (ECM)/powertrain control module (PCM) monitors the high side refrigerant pressure via the A/C refrigerant pressure sensor. The ECM/PCM applies a 5-volt reference and a low reference to the sensor. Changes in the A/C refrigerant pressure cause the A/C refrigerant pressure sensor signal to the ECM/PCM to vary. When the pressure is high the signal voltage is high. When the pressure is low the signal voltage is low. When pressure is high the ECM/PCM commands the cooling fans on. When pressure is too high or too low the ECM/PCM will not allow the A/C compressor clutch to engage. When the DTC is set, the ECM/PCM does not allow the A/C compressor clutch to engage. This is done to protect the compressor.
This diagnostic procedure supports the following DTCs:
• | DTC P0530 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit |
• | DTC P0532 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage |
• | DTC P0533 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage |
• | The engine is running. |
• | The A/C is requested. |
The A/C refrigerant pressure sensor signal voltage is less than 0.2 volt or more than 4.88 volts for more than 3 seconds.
The A/C refrigerant pressure sensor signal voltage is less than 0.2 volt for more than 3 seconds.
The A/C refrigerant pressure sensor signal voltage is more than 4.88 volts for more than 3 seconds.
• | The ECM/PCM stores the DTC information into memory when the diagnostic runs and fails. |
• | The malfunction indicator lamp (MIL) will not illuminate. |
• | The ECM/PCM disables the A/C compressor clutch. |
• | The ECM/PCM records the operating conditions at the time the diagnostic fails. The ECM/PCM stores this information in the Failure Records. |
• | The ECM/PCM will report a value of 0 kPa to the HVAC control module. |
• | The driver information center will display SERVICE A/C SYSTEM. |
• | The A/C OFF segment will illuminate on the HVAC control module. |
• | A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
• | The current DTC will clear when the diagnostic runs and does not fail. |
• | Use a scan tool in order to clear the diagnostic trouble code. |
Important: Be sure to verify that the ECM/PCM engine grounds are secure and clean.
If DTC P0532 or P0533 cannot be duplicated, reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to set occurs. This may assist in diagnosing the condition.
If the condition is not present, refer to Testing for Intermittent Conditions and Poor Connections .
The numbers below refer to the step numbers on the diagnostic table.
This step tests for the proper operation of the circuit in the low voltage range.
This step tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
This step tests for a short to voltage in the 5-volt reference circuit.
Step | Action | Values | Yes | No |
---|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the A/C High Side Pressure parameter is within the specified range? | 0.2-4.88 V | Go to Diagnostic Aids | Go to Step 3 |
Does the scan tool indicate that the A/C High Side Pressure parameter is less than the specified value? | 0.2 V | Go to Step 4 | Go to Step 10 | |
Does the scan tool indicate that the A/C High Side Pressure parameter is greater than the specified value? | 4.88 V | Go to Step 5 | Go to Step 8 | |
Does the voltage measure less than the specified value? | 5.5 V | Go to Step 6 | Go to Step 7 | |
6 |
Does the resistance measure less than the specified value? | 5 ohms | Go to Step 12 | Go to Step 11 |
7 | Test the 5-volt reference circuit of the A/C refrigerant pressure sensor for short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 |
8 | Test the 5-volt reference circuit of the A/C refrigerant pressure sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 9 |
9 | Test the signal circuit of the A/C refrigerant pressure sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 |
10 | Test the signal circuit of the A/C refrigerant pressure sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 |
11 |
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 |
12 | Inspect for poor connections at the harness connector of the A/C refrigerant pressure sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 14 |
13 | Inspect for poor connections at the harness connector of the ECM/PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 15 |
14 | Replace the A/C refrigerant pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- |
15 | Replace the ECM/PCM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | -- | Go to Step 16 | -- |
16 |
Does the DTC reset? | -- | Go to Step 2 | System OK |