Swapping Logic Modules or Chips, Disconnect Battery?

[Turbodave]

Just curious if people disconnect their battery when swapping out logic modules, Smecs/sbecs, or when removing and installing calibration chips.

[tryingbe]

I disconnect my battery every time, why risk it.

I don't have a radio.

[badandy]

Currently I pretty much have to remove my battery to even get to SMEC...so it's a given but if not I would do it anyway.

[Turbodave]

I usually disconnect them as well, and for the longest time I just assumed you were supposed to. One day I accidentally forgot to when swapping the Logic module in the Omni and I didn't notice any problems.

On an SBEC/SMEC car I guess you pretty much have disconnect the battery so you can remove it, but I suppose this could apply to those that have a smaller or relocated battery.

[MiniMopar]

I do it all the time without disconnecting the battery. Technically you should, but I don't bother. This is on an 87 LM car with the hole for the MAP sensor. So I can reach right in there and swap the chip. The standby power for the processor's RAM does not power the EEPROM, so the socket is unpowered as long as the ignition is off. I always discharge myself on the chassis before touching the chip or the LM.

[ShelGame]

I re-flash my SMEC from the drivers seat without ever removing the battery. On the contrary, the battery MUST be connected to be able to power up the SMEC and flash it...

[moparzrule]

I disconnect it everytime, not worth the risk. I use a quick disconnector so it takes 5 seconds with the spin of a knob-
http://cgi.ebay.com/Battery-Quick-Di...QQcmdZViewItem

I also have a garden tractor battery (350 CR) so it's small enough to fit the SMEC out without taking out the battery.

[TopDollar69]

I disconnect the SMEC from the harness, then swap the chip. Seriously, what's the difference If I'm disconnecting power at the battery or the computer? I haven't any issues yet, but I have an extra computer if anything happens. Sometimes we need to learn the hard way.

[minigts]

Never did when I had the LM setup, but with the SMEC I have to remove the battery so it is just part of the process. Of course when I had the LM setup it was TI and I was hoping it would get damaged or break!

[Murphy]

i have this wierd problem with my 87 tona where if i swap chips, sometimes the cal wolnt read right or something? i'll get in boost and I wolnt have enough fuel or i'll goto start it and it wolnt start, disconnect the battery hook it back up again and everything is fine

[turbovanman²]

Never, I just slide the battery out of the way.

[MiniMopar]

i have this wierd problem with my 87 tona where if i swap chips, sometimes the cal wolnt read right or something? i'll get in boost and I wolnt have enough fuel or i'll goto start it and it wolnt start, disconnect the battery hook it back up again and everything is fine

Probably the autocal values being stored in the processor RAM do not blend well with the other cal. Like cal 1 is setup rich, so the LM's autocal value pull fuel out. Then you put in a cal that is setup lean and the additional lean-out in the autocal values make it too lean. I have had this happen and when it does I yank the red cable out of the LM for a few seconds to reset. Since my changes are incremental, I don't usually have problems.

[TurboJerry]

I don't disconnect the battery either. Not for 18 years and counting....

[WickedShelby88]

So are most of the cals you deal with on LM's Russ?

[nBALLS]

I disconnected the battery back in the day, but as time wore on, it was just faster to swap the LM out without messing with the battery. On SMEC and SBEC cars, I move the battery over to make enough room to pull the SMEC/SBEC.

[MiniMopar]

So are most of the cals you deal with on LM's Russ?

Mainly. Mostly because my cars are LM cars. I have done a few SMEC cals "blind". The Daytona is setup for both LM/PM and SMEC operation, but I haven't had the time to mess with the SMEC part. I tried it once and it wasn't getting power, but I didn't have time to investigate.

[86Shelby]

The battery gets disconnected and the keys not in the ignition always, always, always! I have fried a 2 yr old Caddy by not disconnecting the battery. I've also tried diagnosing a fried GLHT due to this type of event. Not any fun.

[2.2turboscotty]

most of the time i disconnect, but sometimes if i'm swaping to test the logic with another one i'll just swap it out without disconnecting the battery.

[chilort]

I've mostly played with the older stuff, but not that much.

The point of removing the battery and grounding yourself first is to reduce electrostatic discharge (ESD). The first, second, or even third time a chip takes a big ESD may not kill it. A big one, or enough little ones can.

Now, the LMs have connectors with uneven pin lengths. On newer stuff, the reason you do uneven pin lengths is so that ground is connected first. I haven't looked enough to double check. But if ground is the first connection, then donn-worry-bout-id.

[BadAssPerformance]

Nope... too many radio setting to re-program