Dodge Challenger Forum banner
1 - 15 of 15 Posts

·
Premium Member
Joined
·
1,431 Posts
Discussion Starter · #1 ·
I was speaking with someone recently and we were talking about the idea of swapping out the OEM PCM and installing another PCM so you could add a tune. Then if it were necessary to take the car to a dealer for service, while still under warranty, you just swap back to the OEM PCM and the factory tune.

He said he believes that the OEM PCM logs mileage and when you pull the OEM PCM out at say 500 miles, swap in the other tuned PCM and drive it for several thousand miles, then swap it out again it will show the descrincy of the milage that accumulate. In other words you arrive at the dealer with 3,000 miles on the odometer and 510 miles on the OEM PCM. The assumption would be you were swapping PCM's.

Thoughts here? I have no idea if this is in fact true but it wouldn't be out of the realm of possible.
 
  • Like
Reactions: challengerfan56

·
Registered
Joined
·
715 Posts
Do a forum search lots of posts on this topic, yes miles are logged in the pcm not to mention a code gets set in the bcm so the dealer/factory will know it has had a unauthorized calibration at one point
 

·
Premium Member
Joined
·
3,400 Posts
I was speaking with someone recently and we were talking about the idea of swapping out the OEM PCM and installing another PCM so you could add a tune. Then if it were necessary to take the car to a dealer for service, while still under warranty, you just swap back to the OEM PCM and the factory tune.

He said he believes that the OEM PCM logs mileage and when you pull the OEM PCM out at say 500 miles, swap in the other tuned PCM and drive it for several thousand miles, then swap it out again it will show the descrincy of the milage that accumulate. In other words you arrive at the dealer with 3,000 miles on the odometer and 510 miles on the OEM PCM. The assumption would be you were swapping PCM's.

Thoughts here? I have no idea if this is in fact true but it wouldn't be out of the realm of possible.
The 2011 already has an unlocked PCM all you have to do is tune it with a Diablo tuner, and simply restore the stock tune before taking it to a dealer, they did not start locking the PCMs until 2015.

A Diablo will vin lock to your car unless you buy a multiple license all you'll need is the Diablo InTune 3, if you buy through Hemifevertuning you can get Seans custom written tune for your car.

https://www.hemifevertuning.com/category-s/97.htm
 

·
Premium Member
Joined
·
1,431 Posts
Discussion Starter · #4 ·
The 2011 already has an unlocked PCM all you have to do it tune it with a diablo tuner, and simply restore the stock tune before taking it to a dealer, they did not start locking the PCMs until 2015.
I understand that and I think you misunderstood my question. I’m talking about cars after 2015 if you swap out the PCM for tuned one and then put back the OEMPCM to take your car to a dealer I believe they know you’ve been running the car with the tune simply because of a mileage log that’s built into it.
 

·
Premium Member
Joined
·
3,400 Posts
I understand that and I think you misunderstood my question. I’m talking about cars after 2015 if you swap out the PCM for tuned one and then put back the OEMPCM to take your car to a dealer I believe they know you’ve been running the car with the tune simply because of a mileage log that’s built into it.
OK I see, many think they can do that and I was one of them, but you cannot do it because of the mileage discrepancy, because there is more than one computer that is recording mileage and if those numbers do not match, error codes are written you cannot erase. And Bam! You're busted!

You'll have to leave the unlocked PCM in the car, but you can always roll the tune back to stock.
 

·
Premium Member
Joined
·
3,400 Posts
When you get an unlocked PCM you have to give your exact mileage so they can record that mileage into the unlocked PCM along with your cars VIN#, once you send that data to them to record, do not drive the car until you swap out the PCM so the cars redundancy will not show a mismatched mileage difference.
 

·
Premium Member
Joined
·
1,431 Posts
Discussion Starter · #7 ·
Even if you leave the non-OEM PCM inside and swap the tune back to factory you’re still busted because it leaves a footprint behind that you were there doing that.

Some people don’t care and it’s no big deal then.
 
  • Like
Reactions: bnichols

·
Premium Member
Joined
·
3,400 Posts
Even if you leave the non-OEM PCM inside and swap the tune back to factory you’re still busted because it leaves a footprint behind that you were there doing that.

Some people don’t care and it’s no big deal then.
I can only speak for myself, it is a warranty issue and in my situation there really was not enough of that left to be concerned with and the dealerships in my area are well know service department idiots and I won't even allow them to change my oil anymore.

So as far as I am concerned warranty wise I don't care, they're not getting their hands on it to discover that anyway, but of course not everyones views are the same.

So if warranty is a concern I suggest waiting until it isn't and then do as you want.

My 2 cents. Ryan
 

·
Premium Member
Joined
·
3,400 Posts
Everyone has their own plans for their Challengers, I started modding mine simply because I knew it was seriously lacking performance when we brought it home and I simply wanted it to be all it actually could be, and in my opinion should be.

I wanted originally to go the dealer route with Scat Pack Stage 1, let them buy it and install it and keep my warranty, but they were clueless, and dumbfounded when I mentioned doing that, so immediately I discovered just because Mopar can offer Stage 1, doesn't mean every dealer is capable of installing it, and for me that changed everything.

So I took a different path.
 

·
Premium Member
Joined
·
3,400 Posts
I was speaking with someone recently and we were talking about the idea of swapping out the OEM PCM and installing another PCM so you could add a tune. Then if it were necessary to take the car to a dealer for service, while still under warranty, you just swap back to the OEM PCM and the factory tune.

He said he believes that the OEM PCM logs mileage and when you pull the OEM PCM out at say 500 miles, swap in the other tuned PCM and drive it for several thousand miles, then swap it out again it will show the descrincy of the milage that accumulate. In other words you arrive at the dealer with 3,000 miles on the odometer and 510 miles on the OEM PCM. The assumption would be you were swapping PCM's.

Thoughts here? I have no idea if this is in fact true but it wouldn't be out of the realm of possible.
I apologize Sir, I should have read your first post thoroughly and I answered out of assumption.

There is more than one computer in the car which is a redundancy to be sure any mileage is accurate and not falsified, so when you swap the original PCM, you send in the exact mileage on the car with the cars VIN# so it can be recorded in the unlocked PCM.

If you drive that car and change the mileage when you install the new unlocked PCM it is automatically red flagged and the dealership will know, many do not realize that and drive the car waiting on the unlocked PCM and they have already shot themselves in the foot, so to speak.

If you don't drive the car when you install the unlocked PCM the mileage will match and no codes will be generated. When the new PCM is installed you disconnect the battery negative terminal, that shuts the entire car down and forces all the computers to run off their internal written memory, which contains the redundant memory boot up check.

Once the PCM is swapped out and the negative terminal is reattached the 2 computers communicate with each other and as long as the information matches all is well, because a cars computer is programmed specifically, it does not have AI capability, as long as the numbers match, the car does not know you changed anything and neither will the dealer.

That information I learned while researching this swapping out process being at that time concerned with keeping what warranty I had left intact.

That is the exact procedure I used to swap my PCM, but since I don't trust the dealership that serviced my car in the beginning anymore, I have not taken it to them to test whether the information I gleaned from an experienced online service technician I conferred with is actually true as far as the dealer not knowing anything was changed.

According to the same technician if the stock tune was rolled back they would be none the wiser, but, as I said I have not tested that.
 

·
Registered
Joined
·
580 Posts
Even if you leave the non-OEM PCM inside and swap the tune back to factory you’re still busted because it leaves a footprint behind that you were there doing that.

Some people don’t care and it’s no big deal then.
Correct. It’s hard coded now. No back door
 

·
Premium Member
Joined
·
1,431 Posts
Discussion Starter · #13 ·
I apologize Sir, I should have read your first post thoroughly and I answered out of assumption.

There is more than one computer in the car which is a redundancy to be sure any mileage is accurate and not falsified, so when you swap the original PCM, you send in the exact mileage on the car with the cars VIN# so it can be
That’s exactly the information I wanted to confirm. I was just wondering how people could swap their PCM and not get caught up in a warranty issue if that was a possible concern for them
 
  • Like
Reactions: screaminduce1550

·
Registered
2017 Challenger T/A 392
Joined
·
846 Posts
Removing your PCM for another unlocked PCM or having your stock PCM unlocked trips a code in the BCM. It's P1400. No way around it and no hiding it no matter what some companies say.
 

·
Premium Member
Joined
·
1,431 Posts
Discussion Starter · #15 ·
Removing your PCM for another unlocked PCM or having your stock PCM unlocked trips a code in the BCM. It's P1400. No way around it and no hiding it no matter what some companies say.
Thank you that’s exactly what I thought.
 
1 - 15 of 15 Posts
Top