Rev up your engines, today I'm going to answer joey's question,
how many computers do modern cars actually have inside them, modern cars have more and
more microprocessors in them because of computerized designs and manufacturing processes, now the
average car these days can have at least 50 different microprocessors inside the car,
while a tesla model s has 62 microprocessors and a mercedes s class I guess it's something
with s, has over 100 different microprocessors on one single car, now of course when I was
a young mechanic they had no microprocessors, the first ones were the early 1970's when
they went to electronic ignition, then they had ignition control modules, and so you had
electronic computer controlled ignition on the car, back in those days everybody called
them the black boxes, and if something went wrong with a car the mechanics would say,
oh maybe it's something wrong with the black box we don't know how to check that out, I
remember one of my father's customers at the gas station when I was a young mechanic had
a ford and it had the new electronic ignition, and the thing would die every once in a while
and they'd take it to the dealer and it wouldn't die and they said, oh we don't know what's
wrong with it you're just going to have to leave it here for whatever amount of time
it takes for us to figure out what's breaking down, they were starting to have problems
with the little black box the little ignition control module that was breaking down, so
I told my father, let's just get one of those and put it in, and yes back in those days
it was just an educated guess on my part, but yeah it fixed the car and it never stopped
dying and the customer was really happy, but you can't just guess on a modern car,
let's say you got 50 of these different things, how are you going to know which one of the
50 is breaking down you know, odds are only 1 in 50 that you're going to guess right on
that one, that's where mechanic like myself have to have all these fancy computers to
analyse all those fancy computers to see what's going down when some of these computer modules
start to break down, so you might well ask, why are they putting all these computers on
cars, well one of the reasons is because they can and of course they can charge a small
fortune fixing them because hardly anybody is going to be able fix it even at the dealer
they have problems with it, but a lot of it has to do with ease of production, it costs
them less money to make them because in the old days if you had one main processor and
it ran everything in the car, that processor had to have a wire going to every single thing
that it was operating, and with the abundance of electronic stuff on our modern cars that
would be an electronics nightmare, there would be wires going everywhere, miles and miles
of wires, so instead they put in small processors, so they can independently operate things and
all these processors can act independently when they need to, they can get information
from a main processors yes, but since there's so many of them in different areas, things
can react faster like safety devices, antilock brakes, traction control, all that stuff,
because their based on what's called computer bus line, you have instead of billions of
wires, you have a main bus line that a lot of information goes back and forth on, just
like say in an area like I am that has fiber optic cable going to the house, you got different
movies streaming, phones lines, computers, everything running on one line, the can run
at various different speeds and frequencies so they don't get messed up with each other,
but of course this leads to one super big problem if your car is wrecked or flooded,
you got all these microprocessors all over the place, if one of them shorts out, then
when I plug my fancy scan tool in to see what's wrong, a lot of times it will do no communication,
it will say no communication with bus, and that doesn't mean that you're not talking
to the bus going down the street, it means that the system has shut down it's information
sharing and you got to figure out what shut it down, let's say you got a mercedes s class
and there's over 100 of these microprocessors, you got to figure out which one of them is
shorting the thing out, and it can be crazy trying to figure that out, if you have a simpler
car that only has 50 different microprocessors, that's still a lot of searching to figure
out what's wrong with the car, now years ago it wasn't as bad, let's say a car had 5 microprocessors
on it, well all you'd have to do was unplug them one at a time, and if you got to the
bad one when you unplugged it, then all of the sudden your machine wouldn't say, no communication,
it would start communicating, and you'd know that there was a problem in that system that
you just unplugged, but when there's 50 of them or more in the car, good luck on that
strategy, cuz some of these sensors their inside the gas tank and the only was you can
get to them is by dropping the gas tank, what are you gonna do take the whole car apart
and then unplug things one at a time, it gets complicated in a modern car, and this had
led to probably the biggest problem in car repair today, there is a real lack of qualified
technicians to work on modern cars, because sadly but truly, many places are paying the
mechanics less and less so that the owners make more profit, their getting a lower quality
of mechanics, cuz hey why should somebody go to school for 2 or 3 years, buy thousands
of dollars worth of tools, to make a job that doesn't really pay all that much, and as the
cars get more and more complex, you need better and better mechanics, not guys that are like,
oh well that's a crappy job maybe I'll try it for a while and try something else, and
I read in a lot of these mechanic trade mags, oh we need to train the mechanic better and
this and that, but really they never get to the root problem, if you're not going to pay
them enough, you're not going to be able to get people in to do all that hard work if
their not going to be rewarded, because if you keep making cars more and more complicated,
yet don't reward the mechanic who have to figure that stuff out, your going to have
a real problem where cars are going to break and nobody is going to be able to fix them
in mass, I personally see that all the time, I have customers that will bring me a car
and they'll say, oh scotty I'm having this problem and I'll say, hey look your car is
under warranty take it into the dealer and get it fixed free, and they say, you know
I took it into the dealer 5 times and they never fixed the thing, I don't care I'll pay
you to fix it, so really that's not a good system, they want to make them more complex
their going to have to start paying the mechanics who fix them more, or their going to have
a bunch of cars that never get fixed right, because let's face it, cars are a major investment,
it's not like your buying a cell phone and then if it break after a year or two you say
oh heck, you throw it away and buy another one, you really don't want to do that with
your car, now yes there's a lot of stuff you can do with your car as it ages, entertainment
system when it breaks down, you can just use your phone and get one of those little portable
speaker systems that sound great and use that for your music system, if a power window breaks
in the back and you don't really need to use it you can just stop using it, but when it
comes to the actual running of the car, all those microprocessors have to work perfectly
or you can't drive the car, because you have to realize in a modern car, you turn the key,
you think the ignition switch it taking battery power and then sending it to the starter,
you got another thing coming, they don't work that way anymore, when you turn the key in
most modern cars, it's not 12 volts from the battery, it will be a 5 volt reference signal
a lot of times, then that goes to various microprocessors, and they check to make sure
everything is as it's suppose to be, then the computer decides, ok now we're going to
send electricity, and it sends 5 volts out to a relay, then the relay bumps that up to
12 volts which goes to the starter to engage on the engine and turn the engine over, and
sure it's cool that you can have a remote that if you live up north you can point it
out the window and start the car up so it warms up in the driveway for you so you don't
have to go outside, but there's a price to be paid for all these microprocessors, and
of course that's, when they do break down they can be a monster to repair, now you have
to realize at least in the US these things are here to stay, because the only way modern
cars can get the gas mileage that they get, have the power that they have, is through
using all these computers to control everything, electronic power steering, electronic ac system
in cars, electronically activated automatic transmissions, they all require these microprocessors
in order to work correctly, so of course now cars are just loaded with these things, which
is one big reason that you never ever want to drive a modern car through any type of
flood water, it rains a lot here in Houston if you watch the news, I've had many customers
do that and even though the car drove through the water and survived and they were driving
it around, sometimes weeks, sometimes months, sometimes even a year or two later, the electronics
will go totally haywire, because most of these microprocessors, their working on a tiny 5
volt reference signal not that much power, and only milli amps of power, thousands of
an amp of power, so any little corrosion that gets built up from water getting in and starting
to corrode the connectors, so somehow getting past the seals and getting into the electronics
will eventually destroy them, and then figuring out what went wrong can be almost impossible,
I mean if a car was wrecked that's the first thing I ask the customer, has your car even
been wrecked if they have a weird problem, they'll say yeah the right front was crushed
in, so then I start checking all the wiring and microprocessors that are on the right
front end of the car, but if it was flooded who knows where to start checking it then,
modern cars can have from 50 to over 100 different microprocessors in them, your driving a mobile
computer, well multiple computers when you're going down the road in any modern car, and
since this is the Thursday segment where I answer a viewers question, place your own
question on the YouTube comments below and I'll pick the best ones to make a single video
to answer your questions, and where else can you find a guy with 50 years of experience
of fixing cars to answer your own question with a video, so if you never want to miss
another one of my new car repair videos, remember to ring that bell!