PCM replacement experience with Pro Tech Auto Systems

[Squiggle05GT]

It's been a while since I've updated you all on my PCM issues with the '05 Mustang GT. After some time saving up, I've finally decided to go with Pro-Tech Auto Systems for an outright PCM replacement.

I'll be sharing my experience with them here, step by step — from ordering to installation — to help anyone else who might be in the same boat. The goal is to give others a solid reference point and a potentially reliable option if you're also dealing with a faulty PCM.

I'll especially keep you updated on the price, service quality, and overall process. Stay tuned if you're considering Pro-Tech or just want to follow the journey!

 

[Squiggle05GT]

Alright I just ordered my PCM replacement, everything went smoothly on the call with Steve who got my order in, the PCM is already preprogrammed, and comes with 2 keys, the guy told me, all I have to do is take the keys to a locksmith and everything should be plug and play after that. In total it was 1,068.93 with my state tax included. which is pretty pricey in my opinion, but hey I think its worth it. I'll update this post when I receive the PCM in the mail, and go through with the process on installing it

 

[Squiggle05GT]

Update: 6/12/25
Today I finally received the PCM I ordered and was eager to wrap up this long-standing issue with my 2005 Mustang GT. I immediately called a mobile auto locksmith, who was able to program 2 out of my 4 keys to the new PCM without a problem. I held onto the other 2 keys just in case — and thank God I did.
I was genuinely excited to finally put this PCM issue behind me, but that excitement quickly turned into disappointment.

First key turn: The car started immediately — but ran like absolute garbage. It sputtered like it was about to stall out or run out of fuel. I plugged in my OBD2 scanner expecting some helpful codes, but got nothing. I then disconnected the battery for about 5 minutes, reconnected it, and let the car idle for another 10. Still no change — the sputtering stayed.
While sitting in the car, I suddenly got a "Check Charging System" alert on the dash. I looked it up (thanks ChatGPT), and it pointed to an electrical issue — likely related to alternator control via the PCM.
I took it for a short test drive, and it felt terrible. Poor idle, sluggish throttle, and it was clearly running rich. When I got home, I scanned again and finally saw two codes confirming a rich condition.

At that point, I had enough. I pulled the "new" PCM out and reinstalled the original one. Used one of the unprogrammed keys — and the car ran like it did before. Not perfect, but at least driveable and way better than with the replacement PCM.
So now I'm out $1,000 for the PCM and $180 for the locksmith — all for something that didn't solve the problem and arguably made things worse.
I'm planning to call Pro-Tech Auto Systems tomorrow to request a refund. But after reviewing their policy, it looks like they charge a 30% restock/reprogramming fee, even if the unit causes issues — unless I can prove it's defective with a dated receipt from another supplier.
To make things worse, while installing it, I got a few light scratches on the back from the tight space (nothing major — and the whole unit was already covered in this weird gray paint, which had a strong chemical smell when I opened the box).
At this point, I just hope they don't try to deny the refund or pin this on me. Honestly, this has been a huge waste of time and money. I wouldn't recommend Pro-Tech Auto Systems to anyone based on my experience.

 

[crjackson]

Thanks for the followup. Good luck with your refund.

 

[Squiggle05GT]

Called Pro-Tech first thing in the morning and asked for a refund — they said "no problem." I grabbed the original box the PCM came in, wrote all the required return info on a slip of paper, taped it to the box, and shipped it out. Cost me about $16 at the post office to send it back with tracking.

Now I'm just waiting for them to receive it, hopefully by next week. Once they do, I should get my refund — though not the full amount. They're charging a 30% restocking fee, which sucks, but getting $700 back is still better than losing the full $1,000.

Once that's handled (fingers crossed it all goes smoothly), I'm heading to MAK Performance here in Miami — should've gone to them from the start, especially for something as sensitive as a PCM/electrical issue.

Anyway, I'll post an update once the refund hits or if anything else happens.

 

[JC SSP]

MAK did the clutch and pressure plate on my brothers 04’ GTO. I don’t remember if it was Willie or Adrian but no complaints.

Let us know how it goes…

 

[Squiggle05GT]

MAK did the clutch and pressure plate on my brothers 04’ GTO. I don’t remember if it was Willie or Adrian but no complaints.

Let us know how it goes…

Yeah, from what I've seen on Google reviews, they seem to be pretty well-respected in the Mustang community here in Miami. I've actually been meaning to check them out for a while now, but I kept putting it off since it's about an hour drive. After everything I've gone through with this PCM situation, though, I'm ready to go all in and finally get this electrical issue resolved. I've already taken care of the major maintenance myself like a full timing rebuild but when it comes to electrical stuff, I'll admit it's just not my strong suit. I'll let the specialists handle it this time.

 

[Squiggle05GT]

I called them today, and they confirmed they received the unit they sent me. They mentioned they'll call me back in about 30 minutes since they're currently processing six other returns that just came in as well. Looks like I wasn't the only one having issues... which isn't exactly a good sign. Hopefully, they'll issue my refund. Fingers crossed.

 

[Squiggle05GT]

Honestly, this is one of the things I hate most about owning an old car—or any old car, really. Some reliable OEM parts just aren't made for them anymore, and tracking them down is a pain in the ass. Finding a decent PCM in my case has been especially frustrating.

 

[crjackson]

It’s been almost 12hrs. Did you get your refund?

 

[Squiggle05GT]

It’s been almost 12hrs. Did you get your refund?

I called again today, about an hour and a half after my previous call, and they finally told me the refund should hit my bank account by this Thursday. I really hope that's true because, honestly, it felt like they didn't care about me as a customer. I was the one who had to keep reaching out the entire time — not once did they follow up like they promised, either by calling me back or emailing any updates about the PCM or refund. In my opinion, there definitely should have been better communication, especially since I'm spending literally a thousand dollars of my own money. Only time will tell. I'll keep you all posted if I receive the refund by Thursday.

 

[Squiggle05GT]

I called again today, about an hour and a half after my previous call, and they finally informed me that the refund should appear in my bank account by this Thursday. I hope that's accurate because, honestly, it felt like they didn't really care about me as a customer as I was the one who had to keep contacting them the entire way, not once did they ever "call back" or "email me" like they said in a few phone calls i had with them, regarding any updates with the PCM or refund. Only time will tell. I'll keep you all updated if I receive the refund by Thursday.

And they DO have my contact information available to them anytime. I even checked my spam on my Gmail, just in-case Gmail was counting them as "Phishing" or "spam"

 

[crjackson]

I hope they deliver as promised, and I expect they Will. Keep us posted.

 

[Squiggle05GT]

Final Verdict:
I received my refund this morning, but I still wouldn't recommend Pro-Tech Auto Systems for a PCM replacement on this Mustang. The lack of communication, broken promises, and delays made the experience frustrating. For nearly $1,000, the customer service should've been much better. Look elsewhere if you want a smoother, more reliable process.