2009 Ford Mondeo Pricing and Specs

It sounds like the stability-control program is throwing up random fault codes that are telling the on-board computer that something’s wrong with this very important piece of safety technology. At that point, the protocol could be to send the car into limp-home mode to avoid having a faulty stability-control system create any problems that could cause a crash. But who knows, because there are literally hundreds of systems on a modern car that could cause this sort of malfunction.

Because the ESP light only comes on sometimes before the limp-home condition occurs, perhaps the two are related but not reliant on each other. While the engine limp-home mode is usually associated with a problem under the bonnet, the ESP light is more likely to be triggered by a problem with the braking or throttle-by-wire system. Certainly, the latter could also trigger a limp-home response from the engine.

Have the car scanned by a workshop and see what fault codes pop their heads up. That will save a lot of time and money compared with changing components until you find the one at fault.

No, you got a good deal from your mechanic.

If you can hear the pump start running when you hit the tank then it could be an earthing or a connection problem, but it could also be a blockage. It's a good idea to refill your tank before the fuel level drops close to empty when there is a much higher chance of the pump picking up rubbish on the bottom of the tank.