TSB in AZ, Part 2 - 2011 Ford Mustang GT 5.0 Long-Term Road Test

2011 Ford Mustang Long-Term Road Test

2011 Ford Mustang GT 5.0: TSB in AZ, Part 2

January 18, 2011


It was like one of those refugee flights, as if the helicopter had lifted off the rooftop just as everything went bad on the ground.

That's how you feel when you abandon a car and fly away on an airplane. The last time it happened with me was in La Paz, when we parked a bunch of cars in a trailer park near the airport because the roads north to the U.S. had been flooded.

At least this time we didn't hit a steer, throw a dented hood into the bushes and drown an engine in a flooded ravine. Instead the 2011 Ford Mustang GT 5.0 was parked safely in the service bay of Earnhardt Ford in Chandler, Arizona. When the proper part arrived, it would be on the road again, but that would be days from now and I couldn't be waiting around.

As you remember, I arrived in Phoenix on a flatbed tow truck after running the Mustang out of gas. The Mustang tried to warn me, but there was a certain failure to communicate on behalf of both parties. And when I did try to give it some gas, the capless fuel filler thwarted me.

Ford Roadside Assistance tow the car for free to Earnhardt Ford, but naturally you won't find any friendly service people waiting for you on a Saturday night. I check by telephone with the service department first thing on Monday morning and then show up in person to describe the circumstances of our breakdown. (Good thing I had someone with whom to stay and a car to borrow besides.) To me, things look promising for a quick repair, since this is a holiday week and there are few other cars in for service.

Three hours later the service writer from Earnhardt Ford calls with the diagnosis. As always, there is good news and bad news. The good news is, the replacement of the fuel pump module would solve the problem and the service could be completed in about an hour. But the bad news is, the part has to be shipped from the nearest Ford parts depot and even emergency service can't get it here until Thursday.

Right away, I start checking the flight schedules to Los Angeles.

Once I escaped from Phoenix on Southwest Airlines, Earnhardt Ford kept me on top of the situation, much to its credit. It emailed me a copy of the paperwork acknowledging the car's entry into the service department. It promised me that the car would be cleaned and readied whenever I was prepared to pick it up. And most important, it forwarded me a copy of the work order, which is how I learned of TSB 10-21-3.

This technical service bulletin (TSB) distributed by Ford to its dealers warns of an issue in both Ford Mustang V6 and V8 models in which the fuel gauge indicator drops from approximately half-full to empty. The TSB precisely describes the behavior that we experienced in our Mustang GT 5.0. The fuel gauge dropping from half or a quarter full. The inability to get more than 7 to 10 gallons into the 15-gallon tank.

As the TSB notes, the Mustang has a saddle-bag-style fuel tank that straddles the driveshaft. There is an electric fuel pump and a fuel-level sensor on the driver side of the fuel tank. There is a fuel pick-up and fuel-level sensor on the passenger side of the tank. The system picks up fuel first from the passenger side and then from the driver side. The fuel level sensors read the fuel levels on both sides and the two values are averaged for display. When the system reads a large difference between the fuel-level sensors, the fuel level indicator goes to empty and the on-board message center wars of limited range.

In the electrical confusion, the pick-up system fails to switch from the passenger side of the tank to the driver side of the tank. As result, the darn thing runs out of gas.

The 2011 Ford Mustang GT 5.0 pulled through and did live again. It's in the Edmunds garage in Santa Monica right now. But there are a few things that we'll be pursuing. What kind of fault frequency must be found before a TSB becomes a recall? Is Ford's policy in this regard different from that of other manufacturers? This TSB 10-21-3 was posted by Ford on October 19, 2010. Should we have been aware of this issue? Should our dealership have been aware of this before we took delivery of the car? And what about the whole capless fuel filler thing?

Ah, questions, questions.

Michael Jordan, Executive Editor, Edmunds.com @ 591 miles

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