Disconnecting the battery resets the settings in my car?

[danegoesonline]

Question. Noong nag palit ako ng battery sa motolite sabi sakin ng technician pag tinanggal daw ang supply sa kotse nag rereset ang settings at minsan nanginginig ang kotse? Sorry narinig ko lang naman po. Can someone enligthen me?

Purpose: Planning to disconnect the battery before I perform engine wash to avoid short circuit.

[StockEngine]

I disconnect my battery, when I clean the throttlebody this is as per service manual. Now when I put it back, the throttlebody has to relearn the position. It takes awhile to learn before switching to ignition on. After learning and obviously the engine is cold, warming up will take awhile. Then it idles.

settings lost or reset to default for my vehicle is the transmission shift points, digital clock and fuel economy unit.

Every manufacturer, already known that at some point the battery will die. and replacing the battery will change many settings but this wont kill the car.

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[Walter]

Don't wash the engine ... Just don't ...

*Stock
How do you "relearn" after reinstalling the throttle body? ...

[SoleusBB]

Don't wash the engine ... Just don't ...

Back in the day, I'd use plastic bags to wrap the alternator, engine coil and distributor then happily spray wash the engine bay of our cars.

Nowadays I wouldn't dare either with all these sensors & computer boxes in place.

Ever the OC though, when the engine's cool I just use a damp rag to wipe the surfaces, taking great care not to pull a wire or sensor somewhere.

[dr. d]

i haven't had my engine cleaned since i got it in 2005.

[StockEngine]

Don't wash the engine ... Just don't ...

*Stock
How do you "relearn" after reinstalling the throttle body? ...

key to "on" position, a system check will be done and you will hear the throttle body moving in and out. by removing the battery, the position values probably were erased.

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[Vodka]

well if that's an ecosport w/ the infamous dual-clutch tranny then you certainly don't want to disconnect the battery completely. for some stupid reason the tranny computer loses its firmware when you disconnect the battery and it'll have to be reflashed at the casa

[the_uglydog]

well if that's an ecosport w/ the infamous dual-clutch tranny then you certainly don't want to disconnect the battery completely. for some stupid reason the tranny computer loses its firmware when you disconnect the battery and it'll have to be reflashed at the casa

If you have a Ford, you can get OBD Link MX from Amazon, load Forescan Lite from the internet to your smart phone and read and reset all the trouble codes yourself. Disconnecting the battery can shut off the low beams in some Fords especially Rangers, cause shift problems and shut off the automatic up and down on the driver's window.

If you have a Toyota it will reset all the programs to original settings. If you have a Camry that is speeding up by itself, disconnect the battery for at least 2 hours 2 times to fix the problem.

[Yatta]

I have these doubts that the ECU actually gets wiped out. The map data after all is stored in a ROM chip. Because if the ECU learns, piggybacks and reflashes will not work or work only a few minutes and the car will go back to stock performance.

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[jick.cejoco]

There are 5 major OBD II protocols. They are not all the same. Different makes have different procedures before disconnecting the battery to prevent amnesia. On lexus, sometimes the BCM does not recognize the ignition key and will not startafter an i terruption of power supply to the BCM.
On GM, sometimes the A/C blows hot air at the main registers when you request A/C operation. Relearninng are usually done with a compatible scan tool.
I usually use the terminal 16 of the DLC 3 for alternate power supply to the BCM and the PCM and ground tterminals 4 and 5to the battery (--). I also use an OBD II memory saver.
Before disconnecting the battery, i scan for current, pending and history diagnostic trouble codes and document or take snapshot pictures of the scan tool while it is connected to the car and using some identifiable background of the car be it the dash or interior should the vehicle owner question, doubt or have trust issue of the procedure. I use these pictures should i need to take the owner to court as evidence.