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For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2001 🢒 S/T Isuzu - 4WD 🢒 DTC 🢒 DTC P0530

DTC P0530 2.2 Liter

Circuit Description

The powertrain control module (PCM) monitors the high side refrigerant pressure via a A/C refrigerant pressure sensor. 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 PCM commands the cooling fans on. When pressure is too high or too low the PCM will not allow the A/C compressor clutch to engage.

Conditions for Running The DTC

The engine is running.

Conditions for Setting the DTC
    • The PCM detects the signal circuit is less than 5 counts (0.09 volt) or more than 250 counts (4.90 volt) when the A/C is requested.
    • The PCM detects the signal circuit is more than 363 psi (4.0 volt) when the A/C is not requested.
    • The condition exists for 15 seconds.

Action Taken When the DTC Sets
    • The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
    • The PCM stores the failure records.
    • The A/C compressor clutch is disabled.

Conditions for Clearing the DTC
    • The DTC will become history if the PCM no longer detects a failure.
    • The history DTC will clear after 40 fault free ignition cycles.
    • The DTC can be cleared with a scan tool.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Tests for the proper operation of the circuit in the high voltage range.

    2.

  2. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.

    3.

  3. Tests for a short to ground in the 5 volt reference circuit.

Step

Action

Value(s)

Yes

No

Schematic Reference: HVAC Schematics

1

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

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls in Engine Controls

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the A/C High Side Pressure parameter in the Powertrain Engine Data 2 list.

Does the Scan Tool indicate that the A/C High Side Pressure parameter display the normal state?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the A/C refrigerant pressure sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the A/C High Side Pressure parameter.

Does the Scan Tool indicate that the A/C High Side Pressure parameter display the normal state?

--

Go to Step 4

Go to Step 8

4

  1. Turn OFF the ignition
  2. Connect a 3 amp fused jumper wire between the signal circuit of the a/c refrigerant pressure sensor and the low reference circuit of the A/C refrigerant pressure sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the A/C High Side Pressure parameter.

Does the Scan Tool indicate that the A/C High Side Pressure parameter display the low state?

--

Go to Step 5

Go to Step 9

5

  1. Turn OFF the ignition
  2. Disconnect the fused jumper wire.
  3. Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the A/C refrigerant pressure sensor and the signal circuit of the A/C refrigerant pressure sensor.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the A/C High Side Pressure parameter.

Does the Scan Tool indicate that the A/C High Side Pressure parameter display the normal state?

--

Go to Step 7

Go to Step 6

6

Test the 5 volt reference circuit of the a/c refrigerant pressure sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

7

Test the 5 volt reference circuit of the A/C refrigerant pressure sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 11

8

Test the signal circuit of the A/C refrigerant pressure sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

9

Test the signal circuit of the A/C refrigerant pressure sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 10

10

Test the low reference circuit of the A/C refrigerant pressure sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

11

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 Special Tools in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

12

Inspect for poor connections at the harness connector of the powertrain control module. Refer to Testing for Intermittent Conditions and Poor Connections and Special Tools in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

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 15

--

14

Important: Perform the program procedure for the powertrain control module.

Replace the powertrain control module. Refer to Powertrain Control Module Replacement in Engine Controls.

Did you complete the replacement?

--

Go to Step 15

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15
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK