High Altitude Stall with Hot Ambient Temperatures - kw 4.8 5.3 6.0 crank fuel GMT610 hard hesitate idle LM7 LQ4 LR4 low MIL nostart no performance pump rough start

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Some 2004 Express or Savana Vans with V-8 engines may experience a stall while driving at high altitude with an ambient temperature of 80 degrees Fahrenheit or greater. This concern normally occurs at altitudes of 5000 feet above sea level or greater. The vehicle may also exhibit a crank no start, hard start, lack of power or rough running condition until the vehicle cools down.

After all related SI documents have been followed, monitor the fuel pressure during the concern. If this condition is present, the fuel pressure will decrease during the condition. If a loss of fuel pressure is noted and no wiring concerns are present, replace the fuel pump module using the latest fuel pump module from the GMSPO parts catalog. There has been a running change to the fuel pump to prevent this occurence. The following 2004 Model Year Vans may exhibit this condition:

- Passenger Express and Savana Vans built prior to March 29th, 2004

- Cut-Away Express and Savana Vans built prior to January 5th, 2004

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

(04 Chevrolet Express G1, G2, G3, H1, H2) and (04 GMC Savana G1, G2, G3, H1, H2)

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