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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Seville 🢒 DTC 🢒 DTC P0533Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage

Object Number: 603425 Size: SF
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Circuit Description

The A/C system uses an A/C refrigerant pressure sensor mounted in the high pressure side of the A/C refrigerant system. The A/C pressure sensor responds to changes in the A/C refrigerant pressure. The PCM uses this information to turn ON the engine coolant fans when the A/C pressure is too high. The PCM also uses the information to disengage the A/C compressor when the A/C refrigerant pressure is excessively high or low. The PCM supplies the sensor with a 5 volt reference and a ground. The sensor returns a signal voltage relative to A/C refrigerant pressures. The PCM monitors the A/C pressure sensor to detect signal voltages outside of the possible range of the sensor. When the PCM detects an A/C pressure signal that is excessively high, DTC P0533 will set.

Conditions for Running the DTC
    • The engine is running.
    • The A/C has been requested.

Conditions for Setting the DTC
    • The A/C pressure sensor signal is more than 4.9 volts.
    • The condition exists for 3 seconds.

Action Taken When the DTC Sets
    • The PCM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM will store the conditions present when the DTC set as Failure Records data only.

Conditions for Clearing the MIL/DTC
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using the scan tool Clear DTC Information function.

Diagnostic Aids

If the condition is intermittent, refer to Intermittent Conditions .

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn ON the ignition, with the engine OFF.
  2. Observe the A/C High Side Pressure display on the scan tool.

Does the scan tool indicate a voltage above the specified value?

3.5V

Go to Step 3

Go to Step 4

3

Is DTC P1639 also set?

--

Go to DTC P1639 5 Volt Reference 2 Circuit

Go to Step 5

4
  1. Turn ON the ignition, with the engine OFF.
  2. Review and record the scan tool Fail Records data.
  3. Operate the vehicle within the Fail Records conditions.
  4. Using the scan tool, monitor the Specific DTC Information for DTC P0533.

Does the scan tool indicate that DTC P0533 failed last test?

--

Go to Step 5

Go to Diagnostic Aids

5

  1. Turn OFF the ignition.
  2. Disconnect the A/C pressure sensor connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the A/C High Side Pressure display on the scan tool.

Does the scan tool a voltage near the specified value?

0V

Go to Step 6

Go to Step 9

6
  1. Leave the ignition ON with the engine OFF.
  2. Leave the A/C pressure sensor connector disconnected.
  3. Connect test lamp between battery positive voltage and the A/C pressure sensor ground circuit.

Is the test lamp ON?

--

Go to Step 7

Go to Step 8

7
  1. Test for poor connections at the A/C pressure sensor.
  2. If the condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 10

8
  1. Disconnect the PCM connector.
  2. Test the A/C pressure sensor ground circuit for an open or poor connections at the PCM.
  3. If the condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

9
  1. Leave the A/C pressure sensor disconnected.
  2. Turn OFF the ignition.
  3. Disconnect the PCM connector.
  4. Test the A/C pressure sensor signal circuit for a short to voltage or the 5 Volt Reference B circuit.
  5. If the condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

10

Replace the A/C pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement in Heating, Ventilation and Air Conditioning.

Is the action complete?

--

Go to Step 12

--

11

Important: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 12

--

12
  1. Review and record the scan tool Fail Records data.
  2. Operate the vehicle within the parameters listed in the Conditions for Running the DTC.
  3. Using the scan tool, monitor the Specific DTC Information for DTC P0533.

Does the scan tool indicate that DTC P0533 passed?

--

System OK

Go to Step 2