What are the consequences of pulling the battery?

I'm sure it has been covered, but I could not find anything in 100 pages of this 3rd gen forum.

But

What is lost and what does it take to recover from a battery swap?

Is the 12v cig outlet "always on" and can be used with a charger to hold memory?

Can the USB plug be used with a "backup battery"? I have a DULL M50000 that is always carried to boost the mobile phones. Perhaps that could maintain the "TACO BRAIN" ;-)

You might know, I'm pretty much techno dumb! ;-)

 

Nothing is lost. Swap with confidence.

 

Soooo during the first run of 3rd gens, and many entune 2.0 we had radios lock up. Very small risk on Tacoma, but rav4 with entune 2.0? Nearly 10% lock up.

I dont ever disconnect the battery. When doing water pumps we tape up the alternator lead, change battery? while running.

I wish toyota used battery saver circuits but they simply dont work.


Anyways, OP. Just do the following, when you reconnect, just turn the key/push button to "On" do not start it, let the radio boot and then start it. This usually prevents low idle with the throttle plate learn.

 

not correct. the trucks computers are reset to default parameters. mpg and shifting won't be as confident as it currently is, the truck needs to re-learn your driving style, and how to stay running appropriately.

the 12v lighter port is ignition powered, so it cannot be used as you're thinking.
the usb is directly connected to the head unit, which is ignition powered, so it also cannot be used that way.

i can't speak if radio settings are lost, as i've changed head units.

 

So what! The truck will start and drive just fine.

PS: When I swapped mine out, I lost no radio presets.

 

consequences??

getting a new fresh one,,, that’s for sure

 

I noticed the automatic climate control settings and mirror compass zone setting were lost. That's about it.

 

What happens if you have a tune like KDMax?

 

Im only aware about idle control learning values. Disconnecting the battery won't wipe learning values. You would need use LV reset function with the scanner.

 

Tune is flashed on there like firmware, non-volatile.

 

Thanks for the response. Got worried for a second

 

I just logged on to the forum to post something about this.

I decided to swap out the head unit with a Stinger unit. My battery positive post had a lot of corrosion so I decided to multi task.

I removed the OEM head unit while battery attached. Unhooked the positive lead while the head unit was out and cleaned the battery.

Reconnected the battery. Installed the Stinger. Won’t turn on. Re-installed the OEM head unit, won’t turn on.

I think I may have caused a reset or something. I eventually ran out of sunlight and now have to figure out what to do with this. I have no radio, phone, hot spot, reverse camera. Everything related to the head unit is out.

 

Check your fuses and relays.

 

I've replaced batteries and disconnected them several times while working on the truck without issue.

Some radio presets are reverted to factory like voice volume and the default radio station tunes to the first FM channel available. Transmission shifting is a little wonky until it relearns within a few hundred miles give or take. Some emissions values also have to be relearned.

Not sure what else if anything.

 

Yeah, that's flashed on the ECU's memory as others mentioned. No effect by changing or disconnecting the battery.

 

Probably blew a fuse. Check fuses related to the head unit.

By the way, it's better to unhook battery negative for servicing instead of battery positive. Functionally it's the same, but you get a spark when reconnecting battery positive.

 

Yeah, this^. Expect the truck to drive a little weird for a bit while it relearns your driving style. Otherwise, it’s not a big deal. You’ll have to disconnect the battery sooner or later when the battery dies, so no worries there.

 

I checked the fuses. I wrote up a separate post about my mishap to see if anyone else had this issue.