Dead Battery

[Jay 02 TA ws6]

Me mum just emailed me from the States, and told me that she tried to start my car, but the battery is dead.

I have a $400 LS1edit tuning on that machine... I think I already know the answer to this question... but that programming is gone, isn't it?

[jspeed97]

Don't think so

Jay,
I'm pretty sure that tuning information is stored on the firmware chip housed inside of the cars computer. It wouldn't be any different from HyperTech Power Programmers, because if you lost the programming just from a dead battery, I would imagine you would hear about people saying their Hypertechs couldn't program their cars again because the car would be back to original specs and the programmer would think that the car was already programmed. I wouldn't worry to much, I'm sure you are okay.

[TraceZ]

No problem

You have nothing to worry about.

[Jay 02 TA ws6]

Then why is it that disconnecting the battery when you are doing mods resets the computer to original specs?

I know I disconnected it one night before I had the tuning done, and it definitely didn't have a clue what it was doing when I turned it on the next morning.

[Black97]

Haven't done any programming nor have I looked into it.

But I think the main programming is done and stored in a ROM chip and it doesn't get erased when the power goes out. Similar to the Bios settings of your home PC.

Other info maybe stored in a RAM chip. The data erases once you loose power. I think it stores the SES codes on something like that. Once you pull the fuse for a while they are gone.

Anybody has some more detail on this?

[Kevin - Blown 95 TA]

The programming is flashed onto the chips and is non-volatile. The short term & long term fueling corrections and codes are in ram and will be wiped when the battery is disconnected or dead. The car will be fine, but it will have to relearn it's optimal settings for 50 miles or so.

[Jay 02 TA ws6]

Well, I got home today, and started her up... to my dismay she stumbled immediately and nearly stalled if I wouldn't have given a blip of the throttle to keep the revs up. It had no idea where to idle, so I took it around the block and performed a wicked tap dance with my feet to keep the revs up while braking or the car was in neutral... very tricky to apply the right brake pressure with your left foot

After a while, she tried idling at 400 RPMs... but wasn't stalling. Finally it came back up to the 800-900 range where it should be.

Do you guys still think all my programming is there?

[fastTa]

Originally posted by Black97
Haven't done any programming nor have I looked into it.

But I think the main programming is done and stored in a ROM chip and it doesn't get erased when the power goes out. Similar to the Bios settings of your home PC.

Other info maybe stored in a RAM chip. The data erases once you loose power. I think it stores the SES codes on something like that. Once you pull the fuse for a while they are gone.

Anybody has some more detail on this?

Rene is pretty much on the money. All of the tables, timing curve, fuel maps, etc. that were flashed will still be there in a EEPROM chip within the PCM. Some of the the constantly fluctuating fuel trim tables and otherwise open loop settings will be reset when power is lost to the PCM. They are stored in a small area of physical memory that needs a small electrical charge in order to retain the data.

Go run her for awhile and let the car fully warm up. Then run the car at WOT through the gears several times. This should help.

[Kevin - Blown 95 TA]

Jay, Jay, Jay...Listen to the two Kevins. We program our heaps.

[Jay 02 TA ws6]

Thanks guys. I especially like the advice to "give her some WOT" runs up through the gears... hahahaha, no problem, Kevins.