Had my gas tank replaced today under Ford's TSB for tank filling problems. Picked up my GT and guess what I noticed? The CEL was on and after I put in 15.4 gallons, the guage read half full and the Info Center stated I have 155 miles to empty. :notnice:
I immediately took it back to the dealer, 5 minutes before service closes and was told by the service guy " it should work" , duh.
They told me the reason the CEL was on was for the low fuel. I have a real hard time believing that as that is what the gas guage and low fuel warnings in the Info Center are for. Yah, whatever. They could not explain the other two wrong readings, so I had to leave it again.
Did someone else have the same problem a while ago? I seem to recall it was a failure to reprogram the computer or something after they replaced the tank. My forum search was futile for any additional information.

I guess the mechanic was so busy listening to his station on my radio when he took it for a test drive (he left it tuned to a station I never listen to, plus the extra five miles that weren't on the work order as the "out" mileage) that he did not notice the CEL. I really dread taking my car in for service anymore. It always comes back with more things wrong than when I dropped it off. :bang:

 

I had the same thing happen after filling it up last week. I put 12.5 gallons in to fill it up. Half way through the gas up, I was in the car and cycled through all the readouts on the info center. When it was full, I noticed the gauge read about 1/2 tank and info center said 140 miles to empty. After driving about 10 miles it slowly corrected itself...no problem since. Maybe it had something to do with me cycling through the info center during the fill-up

 

Doesn't the manual say the car needs to be OFF...so that the computer can properly adjust itself...

 

Well, I am guessing that when they replaced your fuel tank they did not replace all the gas into the new fuel tank. Most of it probably poored out during the process. Go fill it up and see what it does. I had mine replaced today and made sure that I didnt fill it up before I took it to the dealer this morning. I had 45 miles left and when I picked it up I had 29 miles left until empty. Stopped by the gas station on the way home and filled it up. I was good to go no problems. I am sure thats all it is.

 

My gauge started acting up the other day. I had just ordered a wiring harness for another mustang that day. The harness connects the two senders in the tank. There isn't a TSB out yet but on fmcdealer the tech-to-tech message board has some guys explaining the apparent fix. The wiring harness part number is 5R3Z-14407-BA. Hopefully this will cure the gauge problem and the CEL.

 

I've seen a few other posts about the gauges being off and the culprit was always that the car was filled up while turned on. The manual does say to make sure its off or it can't read it properly or something like this.

 

Not the case with mine. My car was already down to 3/4 tank when it started acting up. Car was off when it was filled up and cap was tightened after.

 

Hey thanks Bamaburnum.....

I spoke with the dealer's Service Operations Manager and told him about your posted info on the wiring harness from tech-to-tech. He was impressed with the knowledge available to Mustang owners via this forum. Just another proof of the great things that happen here.
The funny thing that he told me however, was that when the tech went to work on the car, he found all the guages and readings were correct now. He was skeptical that "problems heal themselves" and kept the car the rest of the day to do more investigation. In the end, everything is O.K. They even test drove it for 10 miles and averaged 7.2 m.p.g. so I know somebody was having fun with My Mustang GT.
This was the second time I made the dealer aware of fixes/info/TSB's before they realized what was going on. Just wanted to thank you for your reply. The Service Operations Manager is keeping that info handy in case my problem reoccurs. Then they will do whatever it takes to repair or replace, he told me.

For anybody in the Orlando, FL area, Mullinax Ford in Apopka is where Matt Shrivalle, the Service Operations Manager works. He is terrific. No hassles, no arguments, just a promise to take care of whatever is wrong. He follows through with that promise. I highly recommend Matt Shrivalle as THE service contact person.

 

I have a guage problem also on a V6 2006 coupe. I started the car as normal, had between 1/4-1/2 tank of gas, then while cruising along at 30MPH, the guage dropped to empty and the gas light came on. The car continued running normally and I didn't smell any gas so I know the car still has gas. It looked like it might have been SLOWLY working it's way back up to normal indication, but when I parked at home it was still down around empty. I checked to make sure the gas cap was on good also. Does anyone have any ideas?