This is common for the 04 Pacifica and there has been a technical service bulletin (TSB) about the issue. The solution is to have the body control module (BCM) updated for the fuel gauge parameters. Talk to your local dealer about this TSB to schedule an appointment. The TSB number is 08-038-03
August, 26, 2010 AT 11:53 AM
Hey, a friend of mine has an 04 Pacifica with just about the same problem. She says that when she fuels it up, It only takes 10 gals. I have heard that this car actually has two tanks? Is it just that the fuel gauge reads empty even though there is over half fuel in the car? Or is there a completely different problem altogether?