Hey Guys, I am a college student that is broke and do most of the work on my truck myself. I will never part with my 2000 F-150 5.4L.

I took my truck in and it failed smog as a result of a P1633 code (Low Voltage to Keep alive module). I checked everything (fuses, wiring damaged-shorts) and took it to the dealer who check the circuit and told me my PCM is Bad and wanted $1000 to replace it. I pulled my PCM and opened it up and it looks like new (no corrosion, nothing burnt on the board). I was thinking about buying a used one online or from an auto wrecker but I don't want to spend the money unless I am certain it will resolve my issue.

My PCM is a YL3F-ATE (SNL4), according to ford that is for a 2001 truck, mine is a 2000 (somewhat confusing).

My questions are:
1) If I have my PCM re-flashed/reprogrammed without replacing it do you think the problem will be resolved (my PCM looks new)?

2) I have seen other PCM's online that are similar but not the same (example: YL3F-ATC or YL3F-BAB for a 2000 Ford F-150 5.4L) is the only difference how it is programmed (and can be reprogrammed by the dealer to work for my truck)?

I figure I have to get it reprogrammed either way for my Keys because my PATS...

Any advise would be appreciated. Thanks! I have looked online everywhere.

 

If Ford told you that your PCM is bad, re-flashing it is not an option. A re-flash should only cost around 200.00. Have you traced out all of your grounds to make sure that they are all working. A new looking PCM does not mean that it is not bad!

Good Luck

 

As long as you get a PCM from a 5.4L from your era truck with the same tranny as you, you will be fine. The only issue you may have is with the PATS system. You will likely need to have a new key made.

 

Yeah I know a new looking PCM doesn't mean it isn't bad but maybe I am in denial about spending so much money just to clear a code when the truck is running great.

I didn't check all my grounds. The only thing I did do was I removed all my fuses, check them, use electronic cleaner on them and on all connections under the hood. I also checked for abrasions on my wiring where I could, I didn't have a wiring diagram for the PCM but I read online that the KAM power input was on pin 55 and that is receiving the right voltage.

What concerns me a little was that I installed a Viper remote start in my truck a year ago and I hope that didn't cause any damage (the battery was removed during the install), it has always worked fine though. I don't know how long I have had the P1633 code in my computer. I didn't find out until I took it in to pass smog last month. I even took my truck to the the dealer for a tune up two days before the smog check and they never mentioned the code. It could have been in there since before I bought the truck (2 years ago), when I installed my remote start (1 year ago) or when my battery went bad (6 months ago).

 

"As long as you get a PCM from a 5.4L from your era truck with the same tranny as you, you will be fine."

Hey JCP281,
My truck is a 2000, the tenth generation F-series (10th generation was 97-04). Are you saying I can use any PCM from those years as long it has the same tranny? Why are there so many different PCM's then?

 

Ford introduced new strategies along the way, and small changes were introduced im sure in some trucks. As long as you get a computer from a truck with your same engine and tranny, you should be ok. Works in the Mustang world, I dont see why it wouldnt here.

 

Thanks a lot for your input! It nice when you get your questions answered.

 

Just be aware that your truck may not start. If you get a blinking like crazy theft light, you need to have your PATS reset and a new key made.

 

Yeah I am aware my truck will not start because the Pats. I actually ordered two new transponder keys a few days ago online (I only had one key anyway, you need two working keys in order to program new keys without having to go to the dealer.) Since I must get a new PCM I'll have to add all three in and not just my two new keys. In my opinion, You should always have three keys in case you lose one you can always get a new key without paying to have it reprogrammed.

I still can read my codes from the New PCM without having to have my Pats reprogrammed first I believe.