Hummer H2. Manual - part 1455

21. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure 

(Single Battery) in Engine Electrical. 

22. Purge the fuel sender assembly. 

1. Disconnect the fuel feed line from the fuel filter.  

2. Connect a length of hose to the fuel feed pipe.  

3. Insert the other end of the hose into an empty 3.8 liter (1 gallon) approved gasoline container.  

4. Add 23 liters (6 gallons) of clean fuel into the fuel tank.  

5. Turn on the fuel pump using the scan tool until 2 liters (1/2 gallon) of fuel flows into the fuel 

container.  

23. Inspect for leaks. 

1. Turn the ignition switch ON for 2 seconds.  

2. Turn the ignition switch OFF for 10 seconds.  

3. Turn the ignition switch ON.  

4. Inspect for fuel leaks.  

FUEL RAIL ASSEMBLY REPLACEMENT 

Removal Procedure 

IMPORTANT: If the fuel pump or sender assembly was not replaced, purge the fuel 

sender assembly.

IMPORTANT: An 8-digit identification number is located on the fuel rail. Refer to this 

identification number when servicing or when part replacement is required.

 

2004 Hummer H2 

2004 ENGINE PERFORMANCE Engine Controls (Introduction) - 4.8L, 5.3L, and 6.0L - Hummer H2

  

Fig. 105: View Of EVAP Canister Purge Solenoid & Generator Electrical Connectors & Bracket 
Nut 
Courtesy of GENERAL MOTORS CORP. 

1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure .  

2. Remove the wire harness bracket nut (2).  

3. Disconnect the evaporative emission (EVAP) purge solenoid electrical connector (1).  

4. Disconnect the generator electrical connector (3). 

 

2004 Hummer H2 

2004 ENGINE PERFORMANCE Engine Controls (Introduction) - 4.8L, 5.3L, and 6.0L - Hummer H2

  

Fig. 106: View Of MAP Sensor & Knock Sensor Electrical Connectors 
Courtesy of GENERAL MOTORS CORP. 

5. Disconnect the following electrical connectors: 

z

Manifold absolute pressure (MAP) sensor (1)  

z

Knock sensor (2)  

6. Remove the knock sensor harness connector from the intake manifold. 

 

2004 Hummer H2 

2004 ENGINE PERFORMANCE Engine Controls (Introduction) - 4.8L, 5.3L, and 6.0L - Hummer H2

  

Fig. 107: View Of Right Side Main Electrical Connector 
Courtesy of GENERAL MOTORS CORP. 

7. Disconnect the electronic throttle control (ETC) electrical connector (2). Perform the following: 

1. Disengage the gray retainer.  

2. Push down the black clip.  

3. Disconnect the connector.  

8. Remove the connector position assurance (CPA) retainer (5).  

9. Disconnect the following electrical connectors from the right side of the engine: 

z

Main coil (4)  

z

Fuel injectors (3)  

10. Remove the harness clips from the fuel rail (1). 

 

2004 Hummer H2 

2004 ENGINE PERFORMANCE Engine Controls (Introduction) - 4.8L, 5.3L, and 6.0L - Hummer H2