Keyless Ignition

Pete-IN

Member
Location
Waterloo, IN
For those who are still driving iron from the 20th century, a Keyless ignition just requires the key fob to be in the vehicle. You just push a button on dash once (don't hold it in) and the engine starts. I have always wondered what happens if there is a fuel or other type problem that causes engine to not start. Does it just keep cranking until the battery dies or the starter fries? I asked a car salesman one time and he had no answer.
 
Most newer cars with keys are 'bump start', meaning once you turn the key to start it will keep cranking even if you release the key. Turning the key to start just initiates the start sequence controlled by the engine control module. The starter will crank until the engine starts or the ECM decides it isn't going to start. It's no different if you use remote start or keyless start; all pushing the start button does is tell the ECM to start the car; the ECM takes over from there.
 
I think I read that if it doesn't start in a few seconds, it will stop cranking.

My old 2005 buick has a key. Just bump the key and it will crank until the car starts..

So nothing new.
 
I don't have the schematic for any particular car, but from what I do know about modern computer controlled cars its my understanding IT WONT JUST KEEP CRANKING until the battery or starer fries, not to worry mate. If anyone has the make n model and a schematic they may be able to provide more details.

John T
 
> If anyone has the make n model and a schematic they may be able to provide more details.

I'm pretty sure it's all done in software, John. A schematic probably won't help.
 
My Daughter's car kept cranking until the starter fried.
Also your fob batteries don't last as long in those because they are always talking to the car.
Up side is your can always keep your keys/fob in your pocket or purse and no need to fumble around looking for them. Walk up to locked car and it will open you get close. If they get left in the car it won't let the doors lock.
 
Most brands will time out cranking just like modern keyed ignitions as well. Most keyed ignitions now are a module on the network and don't have any direct starter wire, the computer runs the starter.

We have a 2008 car with keyless, the fob still has the original batteries. Our newer fob has original batteries too. The car is just looking for a code in the keys so the keys don't really drain much. The remote unlock/start using the radio transmitter uses most of the power in the fob. Maybe newer ones have fancier stuff that uses more power.
 
(quoted from post at 05:24:52 05/18/22) Keyledd ignition to me are the tractors you stick a screwdriver in 'cause ya lost the key

Or when you replaced the key switch with a toggle switch and a momentary contact push button.
 
(quoted from post at 04:55:56 05/18/22) For those who are still driving iron from the 20th century, a Keyless ignition just requires the key fob to be in the vehicle. You just push a button on dash once (don't hold it in) and the engine starts. I have always wondered what happens if there is a fuel or other type problem that causes engine to not start. Does it just keep cranking until the battery dies or the starter fries? I asked a car salesman one time and he had no answer.

Typical. Assuming the engineers that design these vehicles are too stupid to think of basic things like this.

True they don't always think of everything, but we're 20+ years into this kind of stuff now and the technology is pretty well refined. If you notice, the kinds of things that are missed now are real "corner cases" where several things have to be just right to make the problem occur.

These cars are instrumented to the gills and everything is interconnected. The computer is programmed to protect the car's systems. Not only can the car sense a no-start condition and stop cranking, it can usually tell you WHY. The systems expect certain things to meet certain criteria in certain amounts of time. If for example it expects to see fuel pressure within 5 seconds, and it doesn't, it will stop cranking after 5 seconds. If the engine is hydrolocked for whatever reason, it will sense an overload in the starter and stop cranking IMMEDIATELY.

A human is far more likely to keep cranking until the battery dies, the starter fries, or the engine is damaged, than the computer. How many times have you seen someone keep cranking an engine until something gives out? How many bent rods have been caused by people trying to crank through a hydrolock?
 
Never had one refuse to start, but I'm sure the engineers took that possibility into consideration when they wrote the software.

When the battery ran down on my 13 Silverado sitting with the radio and automatic lights (unknowingly) on, it tried for a few seconds to crank, then stopped and displayed a low battery message and would not even try to crank until I jumped it. It has a key, but the computer takes over as soon as you turn it to start, no need to hold it.
 
This is why I hope to keep our 2004 Jeep Grand Cherokee and my 1999 Dodge 3500 diesel running at least 10 more years.
They have too much computerized JUNK on them as it is.
 
I like the keyless set up but it is not fool proof. Me being the fool that is. I took my wife to the hospital to have some test done. Because of nnalert they would not let me in the hospital so while I was waiting I went two blocks to pick up medicine. When I can out I could not get in car. The car had been running on my wife's key bob I had left my key bob at home. I had to walk two block back to hospital call my wife and have nurse bring key bob out to me. Then walk two blocks back to pick up the car. Later I found out the car does say you do not have a key bob and you have one try to start the car. Here's where the fool part comes in YOU HAVE TO READ IT
 
I Tried to comment about the keyless cars but but it said I could not comment about the subject. BUT other people did
 
(quoted from post at 06:42:28 05/18/22) I Tried to comment about the keyless cars but but it said I could not comment about the subject. BUT other people did

First off, you just made a comment.

Second off, you probably used a word that's on the "swear filter" such as a competing website name, or an actual swear word.
 
In our new Toyota the key fob evidently times out after a few days of inactivity. If the van sits for a few weeks without being driven a readout on the dash tells us to touch the start button with the fob for recognition. After that touch the key fob is good to go till the next long period of inactivity. As for the doors not locking while the fob is in the van, the doors did lock one time when the van sat in the garage for a few weeks with the key fob in the van. All I can figure out is the fob timed out and was not recognizable by the van. How the doors locked, I will never know. I had to get Marilyn's fob from her purse to unlock the van.
 
In our new Toyota the key fob evidently times out after a few days of inactivity. If the van sits for a few weeks without being driven a readout on the dash tells us to touch the start button with the fob for recognition. After that touch the key fob is good to go till the next long period of inactivity. As for the doors not locking while the fob is in the van, the doors did lock one time when the van sat in the garage for a few weeks with the key fob in the van. All I can figure out is the fob timed out and was not recognizable by the van. How the doors locked, I will never know. I had to get Marilyn's fob from her purse to unlock the van.

Your key fob battery is most likely getting low. That is why it is doing that.
 
You are right. My 2020 Silverado would not start (0nly 650 miles on it) It tried for while then quit trying. Had a bad modular made in other county.
 
Im sure the computer knows what to do. As you may know there are sensors everywhere. If one of them give the computer a no go, it shuts the ignition sequence down.
 
The computer (brain of the car), likely knows if the car has failed fuel pressure, or ignition, and things like that. If it senses something isn't right, it'll shut down the starting attempt.

Fords electric fuel pumps (before push button start), would run a few seconds to build up pressure when key was turned on, and then stop, if you didn't turn the ignition onward into starting mode. So, ... it had fuel pressure senses before push button even came along.

What concerns me, is over riding these functions. Such as, running out of gas, and needing to turn fuel pump on several times to get all the air out of the system, as you use to be able to do with the mechanical key ignition system. I guess you won't be able to do that anymore, other than running your starter through a series of 5 second trys, trying to get the engine to start.
 
Modern cars no longer refuse to start very often. I touch the button and mine starts every time but if it did not start the book says the cycle would stop it from cranking until I push the button again. I cannot even imagine going back to an antique start method where I have to actually put a physical key in the slot. That seems from the dark ages and I would never again own anything like that.
 
(quoted from post at 10:04:58 05/18/22) Modern cars no longer refuse to start very often. I touch the button and mine starts every time but if it did not start the book says the cycle would stop it from cranking until I push the button again. I cannot even imagine going back to an antique start method where I have to actually put a physical key in the slot. That seems from the dark ages and I would never again own anything like that.

"I cannot even imagine going back to an antique start method where I have to actually put a physical key in the slot. That seems from the dark ages and I would never again own anything like that."

Apparently you must no longer own your "1948 Case VAI"???????
 
Wife has a 2021 Subaru WRX and I have a2021 Toyota Tacoma. Both stick shift. And both have conventional keys. I suspect that they think youre to dumb to step on the clutch during starting. With keyless you could start in gear.
 
Everything will be on,but not crank over if you keep your foot off the brake pedal.That's how you plug in the scan tools to check for codes.I was wondering about that a few years ago,took me a little bit before I realized it wouldn't crank over with my foot off the brake.Then they won't just crank over if you step on the brake,you have to hit the button again for off and then on again.
 
"Fords electric fuel pumps (before push button start), would run a few seconds to build up pressure when key was turned on, and then stop, if you didn't turn the ignition onward into starting mode. So, ... it had fuel pressure senses before push button even came along."

Actually, in that era, almost certainly the initial "key on pump run" was a simple timer.

Pump ran for the timed few seconds then stopped until engine was cranked. NO pressure sensor involved.

No way for the 'puter to "know" if the pump had actually run, or not, either.
 
That's good to know. I've only driven a push button start one time, and have wondered about that every sense.
 
I'll try again to tell my experience with key bob's with out saying any bad words. I took my wife to the hospital to have some test run. Because of the (bad word I can't say) the hospital would not let me in. So I went to the drug store and picked up some medicine. I had left my key bob at home and not knowing it have drove on my wife's key bob. I had to walk two blocks back to the hospital call my wife and tell her I needed her key bob. Because of the (bad word I can't say) the nurse had to bring it out to me. I then walked two block back to get the car. I later I found out the car does tell you that you have no key bob and you have one time to start the car. But you do have to read READ WHAT THE CAR SAYS
 
Your right, now that I think about it. If
the pump failed, vehicle could still be
made to try to start. And the absence of
hearing the pump run a few seconds when key
was turned on, was an indication of pump
related failure.

The idea and principle was still there
though. Pump would run, build up some
pressure, and then shut off. That way it
wouldn't burn itself up, if someone left
the key on, with engine not running.

It kind of idiot proofed things. The pump
ran continuously once engine was running.
There was a relief valve and return line.
If engine was not running, the pump would
stop. That way 100 percent of the fuel
wasn't forced through the check valve
return, making it much harder on the pump
to continue to run.
 
Keyless ignition and push button start? Sounds like the 46 ford truck I learned to drive on. Key was broken off in the ignition lock many years ago so it just had the toggle switch on the column and the push button on dash. You had to have a brain to drive a vehicle in those days. How much to pull the choke button. How much to pump the gas pedal before flooding the engine. Seems to me we are getting closer all the time to driverless cars. Just get in, sit there and let the vehicle do all the thinking and work. I don't own any vehicle made in this century and am happy to stay that way.
 
(quoted from post at 13:35:00 05/18/22)
(quoted from post at 10:04:58 05/18/22) Modern cars no longer refuse to start very often. I touch the button and mine starts every time but if it did not start the book says the cycle would stop it from cranking until I push the button again. I cannot even imagine going back to an antique start method where I have to actually put a physical key in the slot. That seems from the dark ages and I would never again own anything like that.

"I cannot even imagine going back to an antique start method where I have to actually put a physical key in the slot. That seems from the dark ages and I would never again own anything like that."

Apparently you must no longer own your "1948 Case VAI"???????
o key...he uses a screwdriver! :roll:
 
In my experience, the push-button start works fine to start the car. But I prefer the old way because it helps me remember to shut off the car and put the key in my pocket. With a rental car that had push-button start, I once left the car running for a couple hours (locked, I think?) in the parking lot of a national park. Returned from all the sightseeing to a running car, with the key in my pocket. I suppose that's my fault, not the car's:-/ But I fail to see the big draw on the push-button start, anyway.
 
I have a 2018 Wrx stick with keyless go. I just pay attention to what vehicle I am driving . We have 3 sticks and 3 automatics.

Vito
 
My 54 Chevy flat bed has a foot push starter button next to the gas pedal. You would have to have your foot mashing the starter button, while pumping
the gas pedal with the same foot, while operating the choke by hand. It's just something you did Stan
 
(quoted from post at 07:55:56 05/18/22) For those who are still driving iron from the 20th century, a Keyless ignition just requires the key fob to be in the vehicle. You just push a button on dash once (don't hold it in) and the engine starts. I have always wondered what happens if there is a fuel or other type problem that causes engine to not start. Does it just keep cranking until the battery dies or the starter fries? I asked a car salesman one time and he had no answer.

The ECM is smarter than most people and will stop cranking before damage occurs .
 

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