You can now program your own PATS keys without a trip to the dealer even if you don’t have two working keys. Here’s what you need:
1) An ELM327 interface for the OBD2 port. Not one of the $10 generic ones, but a real one (expect to spend about $30 or so). Click HERE for the unit I used successfully.
2) A Windows laptop with Forscan installed. Go HERE to download.
3) At least two PATS keys that are cut to physically work in your ignition cylinder. I used a STRATTEC key that was about $10 on eBay. Locksmiths seem to be a little finicky on cutting third party keys, but I eventually found one that did the job for $2.
You’ll need to register Forscan with an extended license. You can get a 2 month license for free by following the instructions HERE.
Detailed instructions for PATS programming are HERE. I’ll condense them to what I did below.
1) Insert a key and turn it to the Run position. Put the ELM327 unit in the OBD2 port, and connect it to the laptop either by Bluetooth (pair it first, then check Forscan settings to select the device) or USB cable.
2) Launch Forscan and connect it to the vehicle. If everything’s working, you’ll see a list of PCM modules that it has connected to through the engine computer.
3) Click the wrench icon, then look for the PATS programming option in the Service procedures. Forscan may either tell you to wait 10-12 minutes while it gets timed access to the function, or go through the incode/outcode procedure to gain access. For incode info, click the detailed instructions link above. On my ’99, I just had to wait 10 minutes to proceed to the next step.
4) Once you’re in, follow the menu to erase all existing keys, then when prompted program each of your PATS keys to the system. Basically, you’ll take the current key out, wait 10 seconds, then insert a key to the Run position and count to three, and do the same with any remaining keys. Once you’re done programming keys, press OK and you can close out Forscan.
This should dramatically simplify V8 swaps, because you can just swap the PATS module that’s paired to the new ECM into your truck, then program your current keys to the new ECM/module. No trip to the dealer required.
Post HERE if you have basic questions and I’ll try to point you in the right direction. For more involved issues, register at the Forscan forum linked above and ask away there.