0:00
Did you know that modern cars have over 20 control units? So, these are electronic control units,
0:06
and they all rely on power supply from your battery or from the alternator. The problem
0:11
is that starting with 2010-2013, depending on the country, manufacturers started using
0:18
electronic control units that require constant power supply. And this is the problem when you
0:25
disconnect the battery because in older cars you could disconnect the battery when
0:29
you saw some error message, warning light, or whatever. You disconnected the battery,
0:34
you reset the ECU, the transmission control unit, or whatever unit you
0:39
want to reset. You plug this battery back and you have solved the problem for $0.
0:46
But in modern cars it may not work like that. It may work in some vehicles;
0:52
for example, in the Honda CR-V, it works because the electronic
0:55
control unit is not that complicated. But in a lot of cars made after 2013,
1:02
and maybe in all cars made after 2017, you will not be able to unplug the battery
1:08
without consequences. So what can happen if you just disconnect the battery in your vehicle?
1:14
First of all, some modules can just lose their memories, so they lose their settings, and when
1:19
you turn on the car you will see a Christmas tree of warning lights, and they will tell you to go
1:24
to the dealership immediately because your car is in the limp mode and it can only drive at 5 mph
1:31
speed. Also, there can be the problems with the anti-theft system. When it comes to anti-theft,
1:38
it also needs power supply at all times in modern cars, because it's a very advanced anti-theft
1:45
system, and it has its own brain and it thinks a lot. It thinks much more than we can imagine, and
1:54
this is the problem for us because when we unplug the battery this anti-theft system goes mad,
2:00
and it can do everything. It can use immobilizer to just immobilize your car,
2:05
and when you plug the battery back, you will start your engine and the engine will not
2:09
even crank because the immobilizer is working. Or your alarm may start going off without a reason,
2:15
and you will not do anything. Just disconnecting the battery will stop this alarm from going off.
2:20
And finally, this car may need reprogramming. You will need to go to the repair shop or to
2:26
the dealership, and they will reprogram the new battery. Or the just after resetting the
2:33
battery you will still need reprogramming. Even if it's old battery, not new one,
2:37
you may need reprogramming, and this costs money, of course. So it answers the question
2:42
why manufacturers did this trick. They want money. They want you to come to them and
2:48
pay $100 or $150 or $200 for resetting the battery, for reprogramming your new battery.
2:56
So what should you do in this situation? There are a couple of things you can try. First of all, you
3:01
can go to a repair shop, and they have the tricks to change your battery without disconnecting the
3:08
entire car from the power. Or you can go to the dealership and pay this $150-$200 for battery
3:17
reset. I mean reprogramming. But, of course, there is one trick that can help you save this money.
3:24
You may use something like a booster or maybe another battery to supply your car with the power
3:30
while you are changing your main battery or when you want to disconnect it. So if you have
3:34
a booster, you can use your auxiliary outlet or maybe the cables that connect your battery. You
3:42
can just connect your booster to these battery cables and then disconnect the cables from the
3:48
old battery. The booster will supply your car with 12 volts, and all the electronic control
3:55
modules will have the power. They will not lose their memory, and then you will connect the new
4:02
battery. And this will help you avoid going to the dealership and paying the money. But this
4:09
will not help you reset the system. So if you just want to get rid of some warning lights,
4:15
this will not help you because you are supplying your car with power, and your modules,
4:22
electronic control modules, they still get this power, and they will not reset. They will still,
4:29
you will still see this warning or error message or whatever you want to reset. So, the new cars,
4:35
they want us to go to the dealership, repair shop, and pay money for diagnostics, for reprogramming
4:41
the batteries, and for other things that we didn't use to pay money for. Sometimes you
4:46
just don't have a choice, or you need to find some independent mechanic who will take $20 for this.
