How Does Start Stop Technology Work in Modern Cars? Everything You Need to Know

start stop technology is a feature that most car owners really dislike and it's something that's been going on in cars for some time well hello and welcome to the car care Channel and in today's video we're going to talk about how does the start stop technology system works in short start stop technology is you come to this traffic light your engine shuts off as soon as you take off it starts in case you're not familiar with this term but the thing that most people don't know is they assume it just starter shuts off starter comes on and what's so special about it but there is so much that had to change with cars to make that system work and work efficiently that we're going to talk about that and a lot more right after this delivered let's start with the history of start stop technology where did they come for that and how did that come about well I actually stemmed from hybrids they realized that in hybrids you know hybrids normally will shut off and start the engine that's just part of their operation they realize that when these hybrids stop at a traffic light they create they create zero emissions many of the times because the engine is not running and they wanted to find a way to integrate that into gasoline cars non-hybrids the first thing is what is the benefit of this star stop technology most people assume it is for gas mileage and it is it does have a small effect on gas mileage but it's so small honestly that you can't even tell the difference but the biggest impact is emissions people usually don't think about emissions emissions is the big thing here is a scenario to make sense you got 15 20 cars in a traffic light they're all idling it's very hot the AC is full blast and maximum load on this engine all this emissions when you're stopped but if they're all these engines are off well we have zero emissions and yes it doesn't make up for when the cars are running and all that but it does something and that's the idea here now Toyota started with their star star stop technology right around 2017 but this information in this video will be somewhat about Toyota but it can apply to other manufacturers because they all did basically the same thing they did not just shut off the engine and start it and let's go they actually had to almost redesign every single system in the car to make this work and work well as you'll find out in the next section so how does start stop technology work we're gonna do something that we haven't done in a while on the channel we're going to keep things simple because they're actually a lot more complicated especially in this one and let us go back in down memory lane to the day where the engineers that initially worked on the system and made it started planning for it see they were given a task and in order to achieve that task there has to be many obstacles and many problem after problem that they dealt with until they reached the final product so if we take a normal gasoline car that doesn't have start stop technology and simply just shut off the Internet it's traffic light here's the problem that you'll have first it will take the engine allow it a long time to actually start back up and then the transmission to reshift into drive and then you while you're waiting for all that to happen your HVAC performance has dropped almost nothing and then we get going see that was too long especially coming from they're looking at a hybrid how it does the transition because you have that electric Drive in hybrids it takes off then the engine starts and everything is seamless and trans basically there's no transition they wanted to duplicate that so people wouldn't feel it like a burden that was the whole thing so they started with the first thing well how do we make this engine start faster and then there's times where you stop at a traffic light the engine is about to shut off and then you immediately start going so how are you gonna you have to wait for the engine to completely stop then start it again it's such a slow operation so they started with a starter see in less than 30 seconds here's how a normal car starter operates you have a motor that's going to actually spin the engine and you have a solenoid when you energize that solenoid a little arm comes out it energizes the motor and pushes to engage the starter to the engine as soon as you let it go this pinion gear that is a little gear that engages on the flywheel it comes back that's why when your car is running and you try to start it again it'll make a grind because that pinion is trying to go and it's not at the same speed of the engine they're just spinning at idle speed and this thing barely spins it at 200 RPM it grinds on it it can't engage because they're uneven speed aha that was the first problem they had well how are we going to do this what if you're stopped in in traffic and the engine is about to shut off it's not shut off completely and then you let go and you want to go well how are we going to start a dungeon that's the first problem so they re-engineered the starter they went to a tandem starter and here's how that works compared to a conventional starter so you have instead of one solenoid that comes out engages the motor and then pushes the opinion they have two solenoids we have one solenoid only engages the starter motor to spin and another solenoid that pushes the pinion gear so if the engine is still spinning and you wanna it's kind of like shutting off and in the in the momentum of the engine to shut off you want to start it again it will actually engage one solenoid spin the starter motor to get it up to speed then the second solenoid pushes the pinion gear in and now we're at the same speed it can start it back up but then when we're in low speed operation or basically this engine is stopped they both engage with the pinion comes out first then the star hits it that makes things a lot quicker and this starter is a very heavy duty starter that spins very quickly some manufacturers have used a reduction motor so it's a very torquey starter that starts the engine or almost idle speed that was the ways they have done this but then things got a lot more complicated the new problem was well we have this fancy new starter that now draws even more electricity because it has two solenoids that need to activate and it it's very rapid and very quick so here's what normally happens in cars some folks actually are not aware of this the starter in a gasoline car is the largest load on the electrical system and the battery ever it draws the most amperage out of any other components actually sometimes all the components combined no matter how advanced cars get so here's the problem well when you start the car normally you notice all the electronics are off once the car starts they all come to live and everything starts loading up and booting up and as we get into newer cars there's a lot of computers that need a few seconds to load up and kind of start functioning so when you do that rapid start we're ready to go well there's going to be a huge dip in voltage on the battery that's normal because the starter takes a lot so how are we going to maintain these all these computers that are ish that are basically on high alert to get going very rapidly from rebooting or just simply shutting off or doing something erroneous because the voltage dropped too low well here's how they did that they added a boost converter just a little device actually available in older hybrids used to be the Fail-Safe that boost converter all it does is it stabilizes the voltage basically a giant capacitor that loads up in any fluctuation it's going to make up for it because we're only talking about a second or two we're not talking about all day long so they only need to stabilize their voltage for a second or two that boost converter will keep the voltage steady while the battery will drop voltage wise because we're starting the engine it'll keep the voltage steady across all other electronics so you won't see a huge dip and things might restart but then come the next problem which was a serious one the battery itself well what if the battery gets weak what if the battery is not able to start this engine well we're just going to get stuck in traffic so they started from the ground up working on the battery and its system it's not just the battery first the battery they cannot put a normal battery because a normal battery will drop as low as 7 volts when you start the engine that's too low and starter will slow down that's just the way it is so they put a special battery that what's special about this battery is it's a battery that can hold high voltage when you give it high load like the starter so they did not want this voltage to drop below nine right around nine volts they needed things to stay up so our capacitor will stay charged and be able to sustain so in addition to the special battery here's what they had to do to kind of monitor this battery because what if gas station down the road didn't know that this car had start stop technology and they decided oh let's just get this regular battery put it in and we'll go well actually the computer every time the starter starts it's going to watch the voltage drop on the battery if it drops below 8 volts it's actually going to know that that battery is not the specified type of battery that we need and it's going to alter the start stop operation accordingly because now we have a a battery that's not capable of these extended periods of start stop events so it's going to kind of change the programming and act accordingly if this battery doesn't drop below 9 volts we're good we have a good battery and it starts noticing that battery degrading severely like it's watching the Ampere straw on it and how low it drops it's basically doing a load test that's what a load test is it's going to supply a certain amount of amperage start ramping it up until the voltage drops a certain point that's how the computer can calculate what's the health of this battery so you notice on these cars you'll actually have an amp sensor on the negative terminal that's how they're able to do this so the battery became a very vital point of the system because without the battery free it could just shut everything down and not do any star stop events but then we arrive at this they were able to shut off the engine they were able to restart it because now we have a battery and a rapid start but what about the event itself when we are in that off time here's the first problem they ran into the HVAC let's start with the heater well cars gasoline cars and they're heaters the heater comes from the hot coolant which is circulated by the engine water pump which is mechanical you shut off that engine well there's no coolant flow if it's very cold outside it's immediately going to be apparent that you don't have coolant flow you're losing heat immediately they did not want that they wanted it to mimic a hybrid hybrids don't do that they'll have heat always even when the engine shuts off so they put in addition to the mechanical water pump they added an electric water pump that does not run all the time and does not run when it's 100 degrees outside only when the system deems that the inside cabin temperature is too low and the ambient temperature is too low we're gonna need that coolant flow to continue so it's gonna when we have a start stop event the engine shuts off it's going to activate that little pump to keep the flow of hot coolant going now we're only talking about a short period of time it's not going to of course the coolant eventually will start getting cold but we have enough reserve the engine is still hot for that colon to continue to circulate and you won't feel any degrade in the heater performance which is pretty cool but then what about our friends in the hot areas and this is the biggest one this is the one that Toyota in my opinion does it a little bit better than others some of them do better actually than Toyota but many towns and that was the surprise so the AC operation I mean you shut off the engine the compressor stops spinning you don't have refrigerant it will take a second for that AC to get muggy and hot that's literally how it is so here's what Toyota did the evaporator again in 30 seconds here's how the AC works this magical gas that is a refrigerant has specific properties when you raise the pressure you raise the temperature when you lower the pressure you lower the temperature you create a restriction in the system the Restriction will drop the pressure down that drop of pressure means less temperature that is your evaporator air passes through it it's very cold the evaporator the air will get cold then that comes back very hot because now it lost it's it's it's not cold anymore because we took the coal from it it goes back to the condenser to get cooled down back to the compressor and off we go that is very very basic AC operation so that evaporator inside the car you have refrigerant going to it all the time to keep it cool so air will pass through it and we have coal there well when you shut off the compressor everything just stops and it is not like the coolant this is rapid it's almost immediate that this evaporator will not be cold anymore so here's what they did which is pretty clever if you haven't seen an evaporator here's how an evaporator looks like well basically for a lack of better word it is a fancy radiator that's all it is in between the tubes and the fins of this evaporator they added a cold storage like little plates all these do is it's a specific design plate that is designed to kind of lose heat and get very cold not freezing but very cold and they hold the cold more than the evaporator itself so you have this plate sitting in there that got very cold when the air is passing through even though we lost the cooling from the evaporator you're still getting some continuous cold air again we're not talking about hours and hours it's only a matter of 20 30 up to a minute two minutes something like that is going to be able to sustain that AC operation while you're stopped and the engine is off that one is really brilliant the next problem was the automatic transmission see here's the way automatic transmission is function they're hydraulic there's no really there is mechanical stuff of course but the way it engages is hydraulically in the way that hydraulic pressure is achieved is you have a big mechanical pump that is spun by the engine all the time and that generates that pressure needed to apply the clutches and get everything going but what happens when you shut off the engine that pressure drops to zero instantly it's just how it works so by the time you restart the engine it's going to take it a few seconds to build up that pressure again so we can get going well that's not going to work so here's what they did they actually integrated an electric oil pump in the transmission that only applies pressure on to only the certain cultures needed or the bands or whichever orientation that specific transmission to keep the first gear engaged so when you come to a stop you have a start stop event engine shuts off you still have the clutch held you're still in first gear ready to go so we're not delaying things more until the transmission builds up pressure and let's go it's already has pressure and it's ready to go as soon as the engine restarts and the mechanical oil pump takes over that little electric oil pump shuts off so that electric oil pump is not running continuously it just runs when we have a start stop event and the last problem they ran into is the brakes believe it or not so gasoline cars they have they have power brakes and the way most of them achieve power brakes is using vacuum from the engine stored in the vacuum booster and that's how what assists you to push the brakes well when you shut off the engine you kind of lost your vacuum and yes cars are equipped where the brake booster is big enough where it holds enough vacuum to have a few brake applications but what if you lost some of that and this is where they had to add a vacuum sensor on the booster to watch it because if it drops too low basically the car could creep from underneath you and that is very dangerous so they had to actively monitor the vacuum Reserve if it drops low we're gonna board start the engine to fill that Reservoir so you're not losing your stopping brakes that is very important then the next thing they did they did all that and things started working they were extremely happy except this if we go back to fuel injected cars did you know that the reason your car takes two seconds three seconds to start when you crank it every car will do that is the engine needs to be at a specific firing position so it would start from the beginning and now we have figured out our crank position figured out our cam position and the computer can start taking over from there and that's why you need a little bit of cranking to to do a full revolution in the engine for it to catch and then it knows where is everything is at mechanically and we fire well if we did that every start stop event that'll work but still not as they're really bothered by that hybrids how they just just start and go immediate because you have the big electric motors doing everything so they took things with a fuel injection to the next level that's the way I'm gonna Sail here's what the computer does here they didn't have to do a lot of mechanical change but they really went overboard with the programming of the computer so here's what the computer does when you have a start stop event and the engine stops the computer is actually going to be closely watching the crank position sensor what that is that is the sensor that picks up where is the crankshaft at where is this piston at where is that piston at where's the cams at through the cam sensor it's gonna kind of capture freeze that image where did the engine stop let's say we stopped the cylinder number two ready to fire when we restart the engine it's going to immediately fire number two and kind of like put a pause and then resume we're not going to have to crank the engine for two three seconds it makes it immediate this engine will start immediately exactly where it left off that is so cool and they actually did have the only change they had to do is the crank position sensor the signal became a little bit richer more detailed so the computer can really tell exactly where that engine is at when it shuts off not only when you give it the signal shut off where it actually mechanically stop and then it would restart it exactly at that same point that is to me and I'm sorry it might be a little car nerd here that is the coolest thing that they ever did in this system now let's talk about the conditions or the moment the computer is deciding should we have a start stop event or not this is a split second decision that the computer will talk to every single sensor a computer in the car to make sure that we are safe to do a start stop event which is something very cool never was possible with older computers that were slower it's only possible today because computers in cars have gotten very rapid here's what the computer checklist will be is my coolant temperature at the correct temperature because if the engine is too cold it is actually not good to jar it with that rapid start and that freeze and continuation it's actually not good for the engine if we need to richen the mixture we need to do all this we are not in in ideal conditions for a start stop operation then the next thing same thing with the transmission we do not want to jar the transmission when it's cold and it needs more pressure that that little pump cannot up reach that's the other thing and then it goes way more than that do we have any doors open that's another thing because are you stopped to open the door and talk to your friend or letting your kids off we don't want that weird up Motion in operation is your seatbelt buckled the drivers are we in a continuous driving with the computers trying to achieve here is are you stopped at a traffic light or not that's what it's trying to achieve the only time you will stop in Drive with your seatbelt buckle with doors closed nothing happened is that a traffic light that's usually of that app is otherwise you'll put it in part or you open the door somebody will come in the car you'll take your seatbelt off this is how the car determines and then the next thing which is very important the HVAC are we demanding more heat than the coolant temperature is because it's very possible that that is the case are we demanding more cooling than the temperature of the evaporator before kind of in extreme cold weather or extreme hot weather are we going to be able with all these modifications that we did to kind of reliably sustain heat or cold if not the computer will not allow a start stop event and that's how it monitors So it's talking to all these sensors at the same time to collect all these data to make a decision are we going for a start stop or not it happens in an instant in a millisecond it can get all this data because it's always watching it now the one limitation of this system this system will not operate in ambient temperatures below 23 Fahrenheit because this is too extreme weather for the system to operate and operate reliably so that's where they draw the line it's like we cannot operate the system under this temperature now it goes a lot more than this because the computer needs to know the condition of the battery that was one of the first thing it checks actually what's the temperature of this battery is this battery overheated hot batteries and very cold batteries don't behave the same as optimal temperature batteries how is the voltage how was the last test of this battery do we have a special battery that is designed for this or do we have a regular battery that is not designed for this it's going to do all these calculations and all these checks in a matter of millisecond to decide are we shutting this car off or not and before you know if we were talking about humans sitting down in a giant table making this decision by the time they they start talking about the first subject the traffic light already turned green so this happens in an instant like computer decides we have a go for start stop or we do not but then there are multiple conditions where the system decides no we're not doing this and in Toyota they will display the reason many other manufacturers will some of them won't but it will actually tell you why you don't have a start stop event if there's any malfunction in any of the systems in the car that contribute to the system it will not allow it if you have any warning lights it will not allow it the temperature is too cold if the battery is too weak or it's charging it'll actually say battery charging if your HVAC demand is too high you need too much heating too much cooling you'll actually say it all these factors the computer have to decide in the millisecond are we a go or are we not a goal now what are some possible complication I mean most people will look at this but like wait a second this is way over complicated and it's just going to make my car less reliable problems and some people have said this causes engine damage well let's talk about a few things yes there is one thing that becomes a casualty of this system which is not something you should be very concerned about but hear me out here the starter that starter we cannot just wait for that starter to seize up and die in the middle of a start stop event to realize hey we're in really bad situations now we're stuck in traffic no they actually realize that we should put an end life of the starter and in Toyotas that number is 384 000 start stop event Cycles when we did the math if you drive your car between 15 and 20 000 miles a year you're talking about just over 10 years of day driving continuous use every single traffic light you're using that start stop it's over 10 years I mean most cars 10 15 years it's not such a bad 80 it replace a startup preventatively but some of them probably not because they're very expensive but most average car that's about how long a starter lasts anyway so they figured we're gonna put a timer it's gonna count from when the car is new one thing you need to know when that starter actually reaches that life it's gonna set a code and it's going to disable the start stop system completely until you replace the starter and reset it one thing I will warn about do not reset your starter counter without replacing the starter because you could create a very dangerous situation if this starter was not replaced and you told the computer it was replaced and it started the counter again and then you're in the middle of a traffic light it shuts off and it won't be able to start the car that could create an accident be very careful that's not something you should be doing the next thing is the battery so the battery for these cars is a special battery it's a specific type of battery that can withstand this load and it is a very expensive battery but the good thing is Folks at Toyota designed it so you can use a regular battery it's just that the system will react differently once it picks up that this is not the special battery it needs it's going to decrease the time that the engine is off and it's going to heavily monitor this battery more to make sure we don't get ourselves in a situation where the battery is too weak to start this engine so that is the good thing but the thing is every time you replace a battery you actually have to go in and tell the computer ideally you'd want to do that even though after some time it'll pick it up but it won't pick it up after a day or two it's going to take a long time to make sure we understand what this new battery is but it will immediately know that there is a new battery just from the way it's behaving the last thing is which is very important some folks have mentioned that the start stop system actually damages the engine folks that is not true not true at all there is no data there is no evidence of this is the case some cars have hundreds of thousands of miles with the system regularly operated nothing happened to the engine the only way the system would actually damage the engine is if you have repeated start stop events when the engine is cold that's actually not good for it you're running very rich and you'll have that linearing fuel around but here's the thing the start stop technology system is very smart I mean it's watching all these things it will not allow that to happen it will not shut off an engine that is very cold it will wait for it to get to Optimal operating condition before it does that so really that's the only case and that's a no case because the computer won't allow it so as you see the system is a little bit more than just shut off the starter and start it again and again folks will say this is way over complicated to achieve nothing doesn't achieve nothing can be annoying I'm with you I understand and the number one question that everyone asks can you permanently disable the system can you just make it to automatically be off when you start the car because you have a little button to disable it folks this is an emissions device I highly suggest you do not alter it you do not modify it as a shop owner it is actually a big problem to alter an emissions device you should not alter it you should not modify it you should not change it that's what the law says what you do to your car is up to you but if you don't like it hit the button every time you start and it won't it won't do anything and will not operate and that's about it that's how the future is going there was times where people dislike fuel injection whoa why could we just have a carburetor why do we have to have all these wires and electronics but that's how life moves on and we have to kind of Advance with it and this is the new technology it is for emissions it does work for emissions not really for gas mileage very much but it does work for emissions and time things are changing with cars we have to change with them and adapt and move on forward folks I hope this video is helpful informative I hope you learned something new if you like it consider giving it a thumbs up if you're not a subscriber consider subscribing to the channel check out some other videos and until the next video folks may the Lord bless you and keep you and you have yourself a wonderful day

Channel: The Car Care Nut

Views: 858,479

Keywords: engine start stop, fuel saving technology, auto start stop, stop start engine, modern car technology, how cars work, toyota, lexus, toyota technology, start stop damage, start stop starter, starter, how starter work, how car ac work, car repair, car mechanic, mechanic, toyota mechanic, the car care nut, car care nut, disable start stop

Id: TTBN8Ic57Gg

Length: 29min 58sec (1798 seconds)

Published: Sat Sep 23 2023