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Battery Disconnect Question C-5

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Old Sep 21, 2007 | 08:46 AM
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Default Battery Disconnect Question C-5

I need to disconnect the battery for an extended period of time. I have heard that the PCM will need to be reprogrammed when the battery is reconnected. Also I have heard the radio has a theft protection that will disable the radio when the battery is disconnected, and the unlock code must be entered before the radio will work again. Is there any other problems to be aware of when disconnecting the battery?
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Old Sep 21, 2007 | 10:05 AM
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Originally Posted by Cujo67
I need to disconnect the battery for an extended period of time. I have heard that the PCM will need to be reprogrammed when the battery is reconnected. Also I have heard the radio has a theft protection that will disable the radio when the battery is disconnected, and the unlock code must be entered before the radio will work again. Is there any other problems to be aware of when disconnecting the battery?
The only thing I've ever had to do is enter the unlock code for the stereo. Never had a pcm issue............
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Old Sep 21, 2007 | 10:22 AM
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Ive unhooked my batery on many occasions and never had a PCM problem

Heres how to get a code to unlock the radio

https://www.corvetteforum.com/techti...=164&TopicID=1

BTW it only locks if the security feature is activated. Deactivate it before you pull the battery and no problems when you reconnect
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Old Sep 21, 2007 | 10:33 AM
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Default Thanks

Thanks for the info.
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Old Sep 21, 2007 | 12:00 PM
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After a battery disconnect you will most likely have to “re-sync” the keyless entry fobs. (Note: NOT “relearn” but simply “re-sync”)

You re-sync the fobs that are already programed to the car by simultaneously holding down the “lock” & “unlock” buttons on the fob until the horn beeps – about 10 seconds.
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Old Sep 21, 2007 | 02:34 PM
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Originally Posted by Cujo67
I need to disconnect the battery for an extended period of time. I have heard that the PCM will need to be reprogrammed when the battery is reconnected.
The long-term tune parameters in the computer will be lost when
you disconnect the battery, but that's about it. The car may
idle funny or seem down on power for the first 50 miles or so
after you get going again. Maybe that's what you heard?
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Old Sep 21, 2007 | 03:19 PM
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Originally Posted by SilvaDragon
The long-term tune parameters in the computer will be lost when
you disconnect the battery, but that's about it. The car may
idle funny or seem down on power for the first 50 miles or so
after you get going again. Maybe that's what you heard?
The PCM does not need to be "reprogrammed". It does do a "re-learn" procedure on it's own like SilvaDragon said.

Wouldn't hurt to jot down your radio station pre-sets too, just in case you need to re-progam them.
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Old Sep 21, 2007 | 04:19 PM
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Default I've wondered

If the PCM has an LSEdit tune in it, will it loose the LSEdit tune and revert back to the factory defaults when the battery is disconnected for a long period of time? I've always wondered about that.
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Old Sep 21, 2007 | 04:27 PM
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Originally Posted by YellowFlash
If the PCM has an LSEdit tune in it, will it loose the LSEdit tune and revert back to the factory defaults when the battery is disconnected for a long period of time? I've always wondered about that.
No. The tune is stored in flash (like a USB memory stick -
it doesn't change unless you change it).
Parameters are stored in a kind of RAM, which just like a
computer is erased when the power is removed.
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