I changed out the PCM in my 2002 F150. It is supposed to be programed to my truck but it won't start. When I turn the key to ON position the THEFT light flashes rapidly. The starter turns the engine over but it won't start. Is my problem the PATS ? I keep reading about different PATS systems and it gets confusing. What should I do next?

 

YES it is.
You cannot change these systems without reprogramming because they work with each other to provide the Theft deterrent feature.
Otherwise it would be easy to defeat and of no value like you just found out..
It's dealer time and you need two keys for reprogramming..
Good luck.

 

Thanks. So I have to let the dealer install the new PCM? Do they re-program the old keys or use new keys?

 

The PCM, the instrument cluster, and the "chipped" keys are all "married" to each other. You cannot simply substitute ANY of those components without them getting "re-married".

This "re-marriage" can be performed by anyone who has the proper equipment (dealer, mechanic, or DIY-er) and it must take place in the vehicle with all parties present.

Of course, all this skips over the obvious question: Why do you think you need a new PCM? They do not fail very often and are frequently mis-diagnosed.

 

My brother is a tech at a large shop and he diagnosed my EGR system problem and erratic drivability problems to a bad PCM.

 

so you put in a new PCM and who programmed it to match the keys and cluster ?

the flashing theft light is a good possibility that this was not done.

 

It's more than a "good possibility", it's confirmation that reprogramming PATS was skipped or failed.

While it's certainly possible that the PCM might be the cause of the EGR subsystem issues, there are many things much higher on the list of probabilities with the PCM being near the bottom of that list. Unless and until those more likely suspects were cleared, I'd be somewhat skeptical of this diagnosis. Since the person who made that diagnosis is also the one who failed to know that reprogramming the PATS would be a requirement and to tell you about that, I'm further skeptical about the original diagnosis.

Good luck.

 

Guess I didn't explain myself well. My brother who did all of the original diagnosis is not around to do the PATS or PCM install. He is well aware of what is involved.
The company I bought the replacement from supposedly flashed it to my VIN number but said they couldn't do the PATS. I was just trying to do this myself and since all I have is AutoEnginuity looks like I may have to go the dealer route.

 

AE can handle this job, but you do need the Ford option, a $199 upgrade.

Alternatively, you can DIY with an Android device, a $10 BT OBDII adapter, and a $5 app.

 

I have the Ford upgrade. Haven't found anything about PATS. Maybe I need to look further?

 

Yes. That feature was added almost 10 years ago. Contact AE if you need help with it.

 

Still haven't changed the PCM. Now getting P1507 and P0443 codes. Reset, runs fine until a day or so later it throws codes again.

 

Neither of those DTCs are related to PATS. Basic maintenance and emissions issues. Google the DTCs for info.

 

So what did you do to get it to start?

 

The 1507 code is an error detected for idle speed too low. Should be 650 rpm +\- 50. Look at your Tach rpm reading, to see it.
.
Code 443 is an EVAP Purge control valve operation error. A fuel tank test diagnostic failure.
Don't change or blame the PCM for doing it's job.
These faults are all engine hardware failures, not computer failures.
Fix the issues causing each code.
Good luck.