Here’s what happened the first time your Mustang Pony acted up: your transmission threw a soft code that wasn’t captured by your vehicles main electronic control module — soft errors are not meant to be captured in the first place. The problem that generated the soft effort then put your Pony into limp-home mode.
Limp-home mode deactivates most of the features of a transmission leaving only forward gearing so that your vehicle can “limp” home or to a repair facility. In this instance, though, the soft error also meant that the limp-home mode was activated so that you could get home. Since it was a soft error, the transmission reset which is why it was okay when you went in for the inspection.
Unfortunately, your transmission then went back into limp-home mode because the soft-code became a hard-code that was flashed and sent to the main electronic control module. In this case, though, there is a problem. It is likely with the one-way direct clutch. The one-way direct clutch helps to keep your transmission shifting smoothly and correctly.
If you think of the one-way direct clutch as “master” clutch in the transmission you can see its importance and why the dealer said that you need a new transmission. For you it is bad news, for the dealer it is good news because just by saying you need a new transmission they are going to whack your credit card for lots and lots of money and they are going to make a tidy sum as well. As it is always less expensive for a dealer to “diagnose and repair” a transmission by swapping in a rebuilt. Yes, it does take time to do this, but not nearly as long as it would take the dealer to do things correctly.
You see, the one-way direct clutch, which slows the overall transmission gearing so that the tranny can shift smoothly from one gear to the next, can be replaced. There are repair kits available for it. The thing of it is that there are so many other potential causes of the P1700 series code that it is much easier for the dealer to do the swap, as well.
You do have to diagnose and check each of the potential problems before you go ahead and swap out the one-way direct clutch and that does take time. To diagnose this problem correctly, the technician has to step through a series of tests to both of the transmission solenoids. They solenoids control the sequence of shifting as their action determines the order that specific clutches are activated. The problem might either be mechanical or electrical so each potentiality must be looked into. There are as many as eight different specific tests that have to be made.
In general, though, it is quite likely that once your technician has gone through the numbers, that it will turn out the one-way direct clutch that has to be replaced. You can certainly save a ton of money if you have your tech swap that particular part because it should cost about $1,400 to complete this repair. Or, you can listen to the dealer and swiftly replace the transmission and pay the $4,000 demanded by the dealer. What move would you make? I’s rather save $2,600 any day, wouldn’t you. Have the one-way direct clutch replaced and you should be all set.