Transmission programming. What does that really mean?
Starting back in the early 90s when Chrysler introduced the A604/41TE transmission, they started requiring shops to perform a “quick learn” once a transmission was replaced or repaired. Basically, the car calibrated the fill times of the clutch packs at whatever pressure the pump was generating. If you didn’t do it, it would shift weird for a while. But, if you were lucky, eventually it would shift normally. This is “programming” of course – and it was 30 years ago.
Now let’s talk about “programming”. Around 20 years after that 41TE Ford introduced it’s FWD 6 speeds, the 6F35/50s. To “program” this transmission there is another fairly tricky step that requires a very special tool. It’s the J2534 interface module, aka a pass through device. This is a box that allows aftermarket shops to program what would other wise be dealer only options. Things like updating software levels and programming solenoid strategies. You don’t need to tow these cars to a dealer for programming, but you will need an adapter and a subscription to that manufacturers service to do it.
So what does solenoid strategy mean? Well starting with those 6F transmissions the manufacturer started adding some tags with 7 and 13 digit numbers. These numbers are what’s called the solenoid strategy. Basically when you build a modern transmission it’s going to have half a dozen or more solenoids. These solenoids aren’t just “on” or “off” like we had 30-40 years ago. They can be fairly precisely modulated but in order to be able to control that modulation correctly the software managing them needs to know their specific flow rates at what amperage and duty cycle. So the manufacturer could order standardized spec’d solenoids but they would cost considerably more and when we’re talking about hundreds of thousands of solenoids a couple of dollars add up. The other option is just to let the manufacturer use whatever solenoids they can get cheapest and compensate with the software. That’s what almost everyone does.
Basically we’re still doing that “quick learn” from 30 years ago, but now we have to tell the ECM how big and what resistance the solenoids are first. What you used to be able to get away with isn’t so easy anymore. From an auto salvage standpoint, the one thing we can do to help is to document those solenoid values when we see them. Often times installers will get parts where the tag is washed off, the cover is broken or they are otherwise illegible. Sometimes the numbers can be retrieved by pulling covers/pans or sending a matching TCM/ECM – but not always.
— Shane Dachel
Warranty Claims Specialist
