Hi, I have a 2001 DRM 3500 5.9L.
Thru eBay I recently purchased a used PCM from a Seller who requires your old PCM part no., VIN no., and current mileage to "flash" it for my van. I bought one from this Seller 2 years ago that has worked fine for many miles and thought I might now have a problem with it but turned out to be something else.
I would prefer to keep this new (used) PCM as a backup for future use if needed but the longer it just sits in storage my van mileage will increase about 10,000 mi. a year. My question is how important to a replacement PCM is your actual mileage compared to what it was "flashed" to. Like what could I expect if I put this new PCM in like 30,000 mi.s up the road? Would it have to be reflashed?
Thanks in advance for any response.

 

Only if you want your odometer to be accurate...... I always thought the cluster remembered that.... maybe I am just getting it confused with GM systems....

 

I don't know if the one time I replaced the PCM it changed my odometer. It seems strange that it would as unscrupulous dealers could reduce the mileage for a sale but there must be some reason the Seller of the PCM asked for the current mileage. I'll contact him and if I can find out the reason mileage needed will post it.
Thanks

 

Got this response to my question from eBay Seller;

"""Most Chrysler vehicles have no issues with the mileage on the PCM not matching the vehicle. But in some cases it can cause an odometer error or emissions test failure as the PCM mileage does not match the odometer."""

 

Ah, now that seems reasonable...... Things have gotten more complicated since I was in the game.

 

I have a spare cluster for my van that I took out of the donor van.
When I swapped it for fun, it showed the other vans mileage.
I went through two PCMs when the 3.9 was in it and it never changed the mileage. Useless trivia - I found out by accident that most like PCMs will run the motor, but would only show codes if it was from a unlike motor. This was when I had a few PCMs from various places.

 

The mileage is stored in the cluster, not the PCM, also the PCM doesn't care what VIN is programmed into it. You can swap a used PCM into your van without any programming as long as the part numbers match.