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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1139 (HVAC Systems - Manual) >> Diagnostic Information and Procedures >> DTC P0530: Air Conditioning (A/C) Refrigerant Pressure Sensor Signal Circuit Too Low or Too High >> Test Description

Test Description

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table:

  1. 4:  If the pressure signal voltage stays high after disconnecting the pressure sensor electrical connector, the signal circuit is shorted to voltage, or the PCM is faulty.
  2. 7:  Tests for a high resistance or for an open in the ground circuit.
  3. 16:  This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). Before you replace the PCM, program the new PCM.
DTC P0530

Step Action Values Yes No
Schematic Reference: HVAC Schematics 
Connector End View Reference:  HVAC Connector End Views  
1 Did you perform the HVAC Diagnostic System Check? - Go to Step 2  Go to Diagnostic System Check - HVAC Systems - Manual 
2
IMPORTANT: The ambient air temperature must be above 3°C (38°F).
  1. Turn OFF the ignition.
  2. Inspect the A/C compressor for free rotation operation.
  3. Start the engine.
  4. Place the HVAC Control Module in the OFF position.
Does the A/C compressor operate?		 - Go to HVAC Compressor Clutch Does Not Disengage  Go to Step 3 
3
  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 PCM Engine Data-2 list.
Does the scan tool indicate that the A/C High Side Pressure parameter is within the specified range?		 0.1-4.9 V Go to Diagnostic Aids Go to Step 4 
4 
  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 is less than the specified value?		 0.1 V Go to Step 5  Go to Step 11 
5
  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the 5-volt reference circuit and the signal 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 is greater than the specified value?		 4.9 V Go to Step 6  Go to Step 9 
6
  1. Disconnect the fused jumper wire.
  2. Measure the voltage between the 5-volt reference circuit of the A/C refrigerant pressure sensor and the ground circuit of the A/C refrigerant pressure sensor.
Is the voltage measurement less than the specified value?		 5.0 V Go to Step 7  Go to Step 8 
7 
  1. Turn OFF the ignition.
  2. Measure the resistance from the low reference circuit of the A/C refrigerant pressure sensor to a good ground.
Is the resistance measurement near the specified value?		 5 Ω Go to Step 13  Go to Step 12 
8 Test the 5-volt Reference circuit of the A/C refrigerant pressure sensor for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 14 
9 Test the 5-volt reference circuit of the A/C refrigerant pressure sensor for a short to ground, for a high resistance, or for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 10 
10 Test the signal circuit of the A/C refrigerant pressure sensor for a short to ground, for a high resistance, or for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 14 
11 Test the signal circuit of the A/C refrigerant pressure sensor for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 14 
12
  1. Disconnect the PCM.
  2. Test the low reference circuit of the A/C refrigerant pressure sensor for high resistance or for an open. Refer to Testing for Intermittent Conditions and Poor Connections and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 14 
13 Inspect for bad connections at the harness connector of the A/C refrigerant pressure sensor. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 15 
14 Inspect for bad connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 16 
15 Replace the A/C refrigerant pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement in Heating, Ventilation and Air Conditioning.
Did you complete the replacement?		 - Go to Step 17  -
16 
IMPORTANT: Perform the set up procedure for the PCM.
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls - 3.4L.Did you complete the replacement?		 - Go to Step 17  -
17
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running, as specified in the supporting text.
Does the DTC set again?		 - Go to Step 2  System OK
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