Thanks Don. I'm going back to the dealer and have them re-train the TPMS. If they give any BS excuse, I'll insists that they call up ford tech hotline and get this done!

By the way, these sensors work by some kind of wireless induction or something right? Or connection via axil? No need to hook up any wires?

 

Yes, sensors are wireless, battery powered, no connection via axle.

I went back to the dealer today to followup on this issue. The Ford tech now agrees that the TPMS can hold only four codes, the ones for the wheels the vehicle shipped with, unless it has been retrained to accept another code, but still a maximum of four. Codes not in the set of four are ignored as if that wheel didn't have a sensor, thus the TPMS fault warning.

I've uploaded a copy of the Ford tech manual page that describes the "TPMS Sensor Training". The "Activation Tool" looks kind of like a key fob, and I've ordered one through the parts department just to get a price. It probably is $600, but if it's $25 I might just buy it <g>.

Dealer stated that they will charge me (didn't ask the price because I won't be paying it) to do any future sensor retraining. Not much of a safety feature IMHO if the customer has to pay to activate it. But that's another issue.

The tech looked into disabling TPMS for me, and concluded it couldn't be cleanly done because of some issue with the "smart junction box" being involved. However, he did suggest a partial workaround. If the full size spare is kept in the vehicle (like in place of the donut spare) and it's code is one of the valid four, then the system will read all four sensors as valid and not raise a warning. However, the wheel with the invalid code is not being monitored for low pressure as it's code is being ignored. I haven't tried this yet since I'm still carrying around the donut spare, but it might work if sensor range is sufficient to detect the spare wheel.

That's all I know. I'm disappointed with the outcome, but I'm concluding this thread.

 

I don't believe that will work either. If it did most of you wouldn't be having a problem because you'd be storing the tire with the TPMS on the vehicle. I think I've read that the sensors ONLY transmitt while the wheels are turning. Maybe to 1) save the battery 2) prevent the car from learning the car next to yours tires at an intersection. So that tire in the vehicle I don't think will transmit its code.

 

I think you are correct. Reading the tech manual again it says:

"If the vehicle has been stationary for more than 30 minutes, the sensors will go into a sleep mode to conserve battery power."

So I guess we just have to learn to live with the warning (and partially disabled TPMS) if we have a full size spare in the rotation. If I rotate the tires every 10k miles, that means the TPMS warning will be occurring for 40k miles out of 50k, or 80% of the time. Knowing what I know now, it was a waste of money to buy a TPMS sensor for the full size spare. I guess that's the bottom line.

 

You might be able to remove the light bulb, old trick from the I dont like the check engine light on days, long gone.

 

Ah the "Car Talk" solution..... black electrical tape . Except it also shows up in the message center, and its nice for the system to work right in case you DO have a flat tire.