PCM question

The 2nd Gen Board is for general questions regarding the second generation of Neons (2000 - current.) Rumors, hints, tips-and- tricks, and all general maintenance and repair questions belong in this forum, as well as beginning modification queries.
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Grey_2004_Neon
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Joined: Wed Mar 06, 2019 5:37 pm

PCM question

Post by Grey_2004_Neon » Sat Mar 16, 2019 4:35 pm

I was wondering, whenever the negative battery cable is disconnected, does the PCM have to "re learn" the settings it had, before battery ground cable disconnection? If so, how far does the car need to be driven, before the re learn process is done?

neoncrazy101
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Location: Central Ohio

Re: PCM question

Post by neoncrazy101 » Sat Mar 16, 2019 8:26 pm

I've never experienced it with my 2gn, even after completely swapping PCM's that were unplugged for months. On my 1gn's though, I've had them where they start for a few seconds and then die after a long battery disconnect. Then I just start them back up and its good. That was always on a 1gn though.

You still having issues with yours running?
95' Plymouth Neon Highline (RIP 293k)
95' Dodge Neon Sport (RIP 218k)
99' Dodge Neon Highline (Totaled, RIP 119k)
97' Dodge Neon Base (Magnum swapped SOHC)
97' Dodge Neon ACR sedan
97' Plymouth Neon Highline
05' Dodge Neon SXT (DD)

Grey_2004_Neon
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Joined: Wed Mar 06, 2019 5:37 pm

Re: PCM question

Post by Grey_2004_Neon » Sat Mar 16, 2019 8:36 pm

Nope, got it going finally this morning, new reman alternator, and the battery sensor. Drives and runs good

occasional demons
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Location: Ashland, Ohio

Re: PCM question

Post by occasional demons » Mon Mar 18, 2019 8:46 am

Just depends on the PCM, and how much actually changed in between power down, and power up.

It took over 700 miles for my 2001 to warm up to the fact I installed a Magnum cam, and ported the head along with a fresh timing belt and water pump.

It ran horrible, and got crappy fuel mileage. It is why I am here, trying to figure out what went so wrong. Then one day, it was like it flipped a switch, and all was good. Power was up, and fuel consumption was down, and it never looked back. I was so close to going back to totally stock too.

I had it disconnected for over two weeks, between cleaning, porting and waiting for the valve grind to be done. I guess it just didn't, like being awakened from it's slumber. I have no idea why it took so long to straighten out. Everything checked out fine, it just didn't want to cooperate.

So they can be simple, or they can be very frustrating, they are just like people...
- Bill

desmodromic wrote:You have to remember what's important here, while they make New humans everyday, they'll never make another Neon.
Skellibert wrote: Fri Oct 13, 2017 3:42 amThis is a daily by the way, not a track car or fun buggy.

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NickKo
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Re: PCM question

Post by NickKo » Sat Mar 23, 2019 1:49 pm

occasional demons wrote: Mon Mar 18, 2019 8:46 am Just depends on the PCM, and how much actually changed in between power down, and power up.

It took over 700 miles for my 2001 to warm up to the fact I installed a Magnum cam, and ported the head along with a fresh timing belt and water pump.

It ran horrible, and got crappy fuel mileage. It is why I am here, trying to figure out what went so wrong. Then one day, it was like it flipped a switch, and all was good. Power was up, and fuel consumption was down, and it never looked back. I was so close to going back to totally stock too.

I had it disconnected for over two weeks, between cleaning, porting and waiting for the valve grind to be done. I guess it just didn't, like being awakened from it's slumber. I have no idea why it took so long to straighten out. Everything checked out fine, it just didn't want to cooperate.

So they can be simple, or they can be very frustrating, they are just like people...
Maybe I am imagining this, but it seems to me (based on my experience) that the 2nd gen PCM's have a longer 'learning curve', compared to 1st gen PCM's - But once it 'learns', it's good.


- Nick
-1998 2-dr SOHC MTX= 52mm TB; Maddog STS
-1999 4-dr DOHC ATX= went to car heaven (junkyard)
-2000 Ply.LX with MTX = Maddog STS; CAI; R/T muffler + Header
-2001 Ddg.ES ATX = UDP, Magnum Header; + Syked PCM 'pending'

-1971 Ply.Scamp SL6cyl. ('Horse Traded' away)
-1968 Chry.300 w/440 V8 (sold)
"MoPar or No Car"

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