Consequences of disconnecting battery?

There's some corrosion build-up on the battery of my 2005 LGT Wagon so I'm going to remove the cables and hold-down and clean it. What if anything will I have to re-program or reset? The only thing I remember changing was to disable the seat belt chime after five(?) bells.

Radio stations will go away and you will reset the ECU learning. After 10 mins of driving the learning will come back, after 20 mins of swearing so will the radio stations

after 30min your trunk monkey will return also

On a stock car, ecu learning is not a big deal.

 

However, ecu learning takes a lot longer than ten minutes. I've been street tuning my car for about two months now and ecu learning is a pita. The IAM comes up in ten minutes but the AVCS takes a little bit longer and AFR learning takes a long time. There's also something odd about the way the 522N base rom handles the low rpm timing. I think there's an additional learned compensation. I don't recall it being there in the 510N rom.

Get one of these and you won't lose anything, assuming you've added a constant power cig socket. If you still have just the stock "key on" socket I guess it won't help much......

dont do it, the car will explode. seriously make sure you get a good corosion inhibitor, i use the stuff from the marine supply stores.

make sure you take the neg off first. it's not a good idea to ground your car's ecu by taking off the positive first....

 

if you've already done it, and pulled the + first, don't sweat it too much; but neg first removal is good preventive medicine.....

Ha ha, no one told me the car would take about 10 seconds of cranking to start the first time. Luckily I stuck with it and it started. It started fine every time after that. I will have to redo the "stop seatbelt chime" function. When will the radio stations come back? I drove two stints of about 15 minutes each and the stations are still missing in action.

I think the above post meant "after 20 minutes of swearing while you remember and reprogram them all, the radio stations will be back"

Yeah, I guess we forgot to mention that. Every time you reset your ECU (reflash, software reset, or disconnect the battery), your ECU will need to "reboot." Rather than cranking it, you can turn the key to the "on" position and let it sit there for ten seconds before cranking. It'll start right up if you let it wait 10 seconds.

if you have a realtime map on there, it will be gone

 

if you have a basemap, it may be affected. on my car, i always check with my AP to make sure its still there...last time i unplugged my battery, to do my fmic, my basemap was still there when i hooked it back up.

make sure you take the neg off first. it's not a good idea to ground your car's ecu by taking off the positive first....

 

if you've already done it, and pulled the + first, don't sweat it too much; but neg first removal is good preventive medicine.....

 

No no no

 

Having a floating ground is a very bad idea. + comes off first.

The reason you take the negative off first is if you bang the wrench against the car while it is on the negative terminal you won't short out the battery. Think about it...metal wrench on positive terminal and now you touch the fender with it...the body/chassis is hooked to the ground.

Negative first. Always.

 

If you doubt it take a spare battery and drop a wrench across it.

Ha ha, no one told me the car would take about 10 seconds of cranking to start the first time. Luckily I stuck with it and it started. It started fine every time after that. I will have to redo the "stop seatbelt chime" function. When will the radio stations come back? I drove two stints of about 15 minutes each and the stations are still missing in action.

 

The trick is not to turn the key to engage the starter. Turn the key far enough so that all the accessories turn on (ACC), then wait for 20 seconds. This allows the ECU to re-calibrate itself, then turn the key to start.

Thanks, but where were you when I needed you :-)

 

The trick is not to turn the key to engage the starter. Turn the key far enough so that all the accessories turn on (ACC), then wait for 20 seconds. This allows the ECU to re-calibrate itself, then turn the key to start.

Ah, you'll probably get the chance to disconnect the battery again at some point

Sorry if reading this post drains your IQ, but how do you disconnect the battery. I heard this is good to do when installing h.i.ds, but i've never disconnected a battery before. you just grab a wrench and unscrew the negative side, then the positive side? Wouldn't there be a risk of getting shocked? (Sorry, I didn't pay attention in science class).

Sorry if reading this post drains your IQ, but how do you disconnect the battery. I heard this is good to do when installing h.i.ds, but i've never disconnected a battery before. you just grab a wrench and unscrew the negative side, then the positive side? Wouldn't there be a risk of getting shocked? (Sorry, I didn't pay attention in science class).

 

The only thing you should worry about is while you are undoing the positive cable, make sure the wrench doesn't touch "ground", namely any metal surface. Batteries don't have enough voltage or amps to shock you, but you don't want a blast from any capacitors (normally used with HID headlamps) or any ignition-related components which step up the voltage.

Get one of these and you won't lose anything, assuming you've added a constant power cig socket. If you still have just the stock "key on" socket I guess it won't help much......

 

I have been wondering if this would work with our cars. I was shown this trick buy the truck mechanic at work.

negative first, and negative last (when putting back on)