wabalaba

Last night, at a gas station, I discovered that I could "turn the car off" (removing the key)--but the car stayed running! I tried a bunch of times to get the switch to engage and I just could not shut the car off.
I could turn the key to any position and it felt normal (I can feel the detents) but the car itself stayed in RUN no matter what I did.

Finally, when I got home, the switch worked perfectly like normal and the car shut right off (go figure).

So something's failing in there! Has anyone had this problem? Is it just the lock cylinder that I have to replace, or the whole switch unit?

Thanks for your help!

wabalaba

So, I'm narrowing down that probably it's just the cylinder itself that's failling. I can replace that easily enough, but I will check the voltages through the ignition switch tonight to be sure it's working.

Can anyone confirm for me whether either or these part swaps requires Ford to reprogram anything? I have the two original keys for the car (both can start it). Can I just match the tumblers in the new cylinder to the old one and/or plug in a new ignition switch and be on my way?

Thanks a lot!

Derf00

For the ignition switch itself no. Only if you change the lock cylinder would a reprogram be needed.

wabalaba

Thanks a lot, I appreciate the help!

wabalaba

For anyone else dealing with this issue in the future, here's some info I found about replacing ignition switch and lock components and the PATS system.

The Passive Anti-Theft System is described here in the manual:
Quoting from the page:
PATS will disable the vehicle from starting if there is:

• a damaged PATS key
• an unprogrammed PATS key
• a non-encoded key (a conventional key or one that does not have any electronics)
• damaged wiring
• a damaged transceiver
• a damaged PCM

It seems like the system doesn't keep track of the specific lock cylinder or ignition switch used (unless that falls under "damaged wiring?"). From what I've found, the system stores the key security code(s) in the PCM; when you insert the key, an antenna around the key cylinder reads the RFID chip in the key. This "transceiver" can be replaced without reprogramming (see here, in the manual, and here ) and is separate from the lock cylinder.

The manual doesn't state explicitly that the ignition switch and cylinder can be replaced without reprogramming. However, the section for replacing the ignition switch and for replacing the key cylinder make no mention of PATS at all.
Here are three videos dealing with the lock cylinders. The first one is very informative about replacing the tumblers, the second one is basically a shorter version of the same thing. The last is by 1A Auto and is also about how to do this repair.

None of these mention reprogramming, so I suspect it is safe to repair the ignition switch and the lock cylinder at home without any risk of needing to reprogram if you continue using the same keys as before. It looks like the PATS is basically just the PCM reading the RFID chip in the key and nothing else. But my bank account will soon find out if I'm wrong...

I had the key cylinder out last night and it seems fine. The ignition switch has some play in the detents and I think there might be a voltage problem at the pins but I'm a ****ty electrician. I'll report back if swapping this solves my problem or sets the car on fire.

Derf00

Good finds!

wabalaba

One more update for anyone in the future with this issue--turns out it may not have been either the cylinder lock or the ignition switch. It may have been a damned remote-start device the previous owner installed!

After replacing the ignition switch and the lock cylinder and getting nowhere, there was finally a "click" from inside the dash that made me realize I might be looking in the wrong place: the car came with an aftermarket remote-start kit that I disabled years ago. Seems like it might have turned itself on again somehow, because once I tried re-shutting-it-down, my problems disappeared! Now, the car starts and shuts off completely normally.

Anyway, it's working and re-coding the key tumbler was fun!