Test Description

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The number below refers to the step number on the diagnostic table.

5: This step tests the ability of the A/C refrigerant pressure sensor to create a voltage signal for the ECM to monitor the A/C refrigerant pressure. Measure the voltage at the A/C refrigerant pressure sensor, if the voltage is measured at the connector for the sensor, misdiagnosis will occur.

DTC P0530 (LB7)

Step	Action	Value(s)	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	Does the scan tool indicate that DTC P0530 is current?	-	Go to Step 3	Go to Diagnostic Aids
3	Turn OFF the ignition. Disconnect the A/C refrigerant pressure sensor. Turn ON the ignition, with the engine OFF. Measure the voltage from the 5 volt reference circuit to the low reference circuit of the A/C refrigerant pressure sensor. Does the voltage measure near the specified value?	5 V	Go to Step 5	Go to Step 4
4	Measure the voltage from the 5 volt reference circuit of the A/C refrigerant pressure sensor to a good ground. Does the voltage measure near the specified value?	5 V	Go to Step 7	Go to Step 6
5	With the A/C refrigerant pressure sensor disconnected, connect a jumper wire between the A/C refrigerant pressure sensor and the electrical connector of the A/C refrigerant pressure sensor for the following circuits: The 5-volt reference circuit The low reference circuit Measure the voltage at the A/C refrigerant pressure sensor terminal for the A/C refrigerant pressure sensor signal. Does the voltage measure less than the specified value?	1.5 V	Go to Step 8	Go to Step 9
6	Test the 5-volt reference circuit of the A/C refrigerant pressure sensor for a short to ground, 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 13	Go to Step 10
7	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 13	Go to Step 10
8	Test the signal circuit of the A/C refrigerant pressure sensor for a short to ground, 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 13	Go to Step 10
9	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 in Wiring Systems. Did you find and correct the condition?	-	Go to Step 13	Go to Step 11
10	Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 13	Go to Step 12
11	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 13	-
12	IMPORTANT: Program the ECM. Replace the ECM. Refer to Engine Control Module (ECM) Replacement in Engine Controls-6.6L.Did you complete the replacement?	-	Go to Step 13	-
13	Use the scan tool in order to clear the DTCs. 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