Hummer H2. Manual — part 1943

Diagnostic Aids

For an intermittent, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

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

3: Tests for the proper operation of the circuit in the low voltage range.

4: 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.

5: Tests for a short to voltage in the 5-volt reference circuit.

6: Tests for a high resistance or an open in the low reference circuit.

DTC P0530

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 -

Automatic

2

1. Turn ON the ignition with the engine OFF.

2. With a scan tool, observe the A/C Pressure

Sensor parameter in the Powertrain Engine Data
list.

Does the scan tool indicate the A/C Pressure Sensor
parameter is within the specified range?

0.1-

4.9 V

Go to

Diagnostic

Aids

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 Pressure

Sensor parameter.

Does the scan tool indicate that the A/C Pressure
Sensor parameter is less than the specified value?

0.09 V

Go to Step 4

Go to Step 10

1. Turn OFF the ignition.

2. 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.

2004 Hummer H2

2004 HVAC HVAC Systems - Automatic - Hummer H2

4

3. Turn ON the ignition, with the engine OFF.

4. With a scan tool, observe the A/C Pressure

Sensor parameter.

Does the scan tool indicate that the A/C Pressure
Sensor parameter is greater than the specified value?

4.9 V

Go to Step 8

Go to Step 5

5

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 low reference circuit of the A/C
refrigerant pressure sensor.

Does the voltage measure less than the specified
value?

5.1 V

Go to Step 6

Go to Step 7

6

1. Turn OFF the ignition.

2. Disconnect the negative battery cable.

3. Measure the resistance from the low reference

circuit of the A/C refrigerant pressure sensor to a
good ground.

Does the resistance measure less than the specified
value?

5 ohm

Go to Step

12

Go to Step 11

7

Test the 5-volt reference circuit of the A/C refrigerant
pressure sensor for a short to voltage. Refer to Circuit
Testing and Wiring Repairs in Wiring Systems.
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 in Wiring Systems.
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 in
Wiring Systems.
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 in Wiring Systems.
Did you find and correct the condition?

-

Go to Step

16

Go to Step 13

11

1. Disconnect the powertrain control module.

2. Test the low reference circuit of the A/C

refrigerant pressure sensor for a high resistance

-

2004 Hummer H2

2004 HVAC HVAC Systems - Automatic - Hummer H2

SYMPTOMS - HVAC SYSTEMS - AUTOMATIC

1. Perform the Diagnostic System Check - HVAC Systems - Automatic before using the Symptom Tables

in order to verify that all of the following are true:

z

There are no DTCs set.

z

The control module can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to

or an open. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.

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 in Wiring
Systems.
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 powertrain control module. 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

16

Go to Step 15

14

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

16

Go to Step 15

15

Replace the powertrain control module. Refer to
Powertrain Control Module (PCM) Replacement in
Engine Controls - 4.8L, 5.3L, 6.0L.Did you complete
the replacement?

IMPORTANT:

Perform the programming procedure for the
powertrain control module.

-

Go to Step

16

-

16

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

IMPORTANT: The following steps must be completed before using the symptom tables.

2004 Hummer H2

2004 HVAC HVAC Systems - Automatic - Hummer H2

z

Air Delivery Description and Operation

z

Air Temperature Description and Operation

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the HVAC System. Refer to Checking

Aftermarket Accessories in Wiring Systems.

2. Inspect the easily accessible or visible system components for obvious damage or conditions which could

cause the symptom.

3. Verify the A/C compressor clutch turns freely and is not seized.

4. Verify that the customer is using the correct key to enable personalization.

5. The A/C compressor will not operate in cold outside air temperatures. Refer to Air Temperature

Description and Operation .

6. The following conditions may cause window fogging:

z

Wet carpet or mats

z

High humidity

z

Interior water leak

z

Blocked A/C evaporator drain tube

z

Maximum passenger capacity

z

Blocked body pressure relief valves

7. Inspect the air distribution system for causes of reduced air flow:

z

Obstructed or dirty passenger compartment air filter, if equipped

z

Blocked or damaged air inlet or outlet vents

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for
Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

z

HVAC Compressor Clutch Does Not Engage

z

HVAC Compressor Clutch Does Not Disengage

z

Blower Motor Always On

z

Blower Motor Inoperative

z

Blower Motor Malfunction

z

Too Hot in Vehicle

z

Too Cold in Vehicle

z

Air Delivery Improper

2004 Hummer H2

2004 HVAC HVAC Systems - Automatic - Hummer H2