How to send power to momentary switch one time.

Thread Starter

hootistigglebits

Joined Jul 5, 2022
8
I have a factory installed automotive momentary switch that has power once the car is running. Every time I start the car I have to press this button once in order to change the drive mode and I would like to automate this. What all components do I need to be able to activate this switch one time when the circuit has power?
 

ci139

Joined Jul 11, 2016
1,858
the problem might be not emulating the button press - but confirming the mode had successfully changed by that
 

djsfantasi

Joined Apr 11, 2010
8,390
And is it even legal where you live to make such a modification? It could result in being assessed hefty fines or voiding your car insurance (thus making it illegal to drive your car on the street).
 

MisterBill2

Joined Jan 23, 2018
12,399
And is it even legal where you live to make such a modification? It could result in being assessed hefty fines or voiding your car insurance (thus making it illegal to drive your car on the street).
Why even make such a statement when you know nothing about the TS? And what sort of police state are you fmiliar with where such rules exist? You (DJSF) must have had some terrible experience to provide such dire warnings.
 

Reloadron

Joined Jan 15, 2015
6,698
I have a factory installed automotive momentary switch that has power once the car is running. Every time I start the car I have to press this button once in order to change the drive mode and I would like to automate this. What all components do I need to be able to activate this switch one time when the circuit has power?
It all depends on knowing exactly what the button does? How it's configured in the system as pointed out in post #3. If the button needs pressed only after engine start or if the button is pressed only after ignition is on also figures into things, I assume by your post this is after engine is running? Auto activating a switch is not a problem but one must know exactly what the switch does and why it does it. Sometimes auto activating a switch is a good idea and other times not a good idea. Changing drive mode as in GOAT (Goes Over All Terrain) for example?

Ron
 

Thread Starter

hootistigglebits

Joined Jul 5, 2022
8
It all depends on knowing exactly what the button does? How it's configured in the system as pointed out in post #3. If the button needs pressed only after engine start or if the button is pressed only after ignition is on also figures into things, I assume by your post this is after engine is running? Auto activating a switch is not a problem but one must know exactly what the switch does and why it does it. Sometimes auto activating a switch is a good idea and other times not a good idea. Changing drive mode as in GOAT (Goes Over All Terrain) for example?

Ron
When the engine is running the car is in comfort mode, but I always put it in sport mode by pressing the switch once. Because of this I have to press it every time I turn the car on. Sadly there's no way to change this in the cars computer. I'll disassemble and hook my meter up to it to see how it works exactly.
 

MisterBill2

Joined Jan 23, 2018
12,399
Unfortunately neither of the figures tells us what we need to know to make a neat connection for an external anything.We see a map of the switch contacts, which I am guessing that they are small push buttons with two ins for each switch side, not two separate switches. AND it shows some device connected across each switch, which is not common.
Given that the plan is not to hack into the switch assembly we need to know the switch connections at the external wiring attachment point, so that external connections to (something) can be added. Possibly working with a relay operated during engine cranking. The momentary pulse will need to be isolated contacts,

I am seeking a way to take my Caravan OUT of the performance mode, because squealing the tires starting out at a light always attracts the attention of the nearby traffic safety officer. It is not from stomping on the pedal, it happens with anything other than a very gentle touch. Certainly a major irritation.
 

djsfantasi

Joined Apr 11, 2010
8,390
Why even make such a statement when you know nothing about the TS? And what sort of police state are you fmiliar with where such rules exist? You (DJSF) must have had some terrible experience to provide such dire warnings.
That’s why I asked if was legal where he lived. Because his profile doesn’t mention that.

If he lives in the US and that button is part of the safety system, then in the US, it is ILLEGAL to modify that switches function.

I don’t know where he lives nor do I know if that switch is considered to be part of the safety systems. But if he lives in the US and the switch is part of a safety system (such as a safety interlock), then my latter comments are true.
 

MisterBill2

Joined Jan 23, 2018
12,399
What are you talking about? "Safety System?? What would that be??? Traction control?? Airbag inhibit?? Stability control??
No, it is none of those. Tossing out warnings about fictional hazards and rules does not ever benefit anybody.
 

Reloadron

Joined Jan 15, 2015
6,698
Well alrighty. So when you start the car the mode is similar to the various GOAT modes I mentioned. The car defaults to Comfort mode and you really want Sport mode. I assume that to be correct. With that in mind you want to simulate a button push for sport mode. So on engine start, engine running you want a delay on make for about 1 second, followed by maybe about a 1 second pulse or less simulating a button press? Would that be about it? Rather than the default mode just auto switch to the sport mode correct? So we need an engine running signal to start things and I have no clue where to get that on your vehicle. You can likely buy a "one shot" timer which will give you a one second pulse. Drive a small relay which simulates a button press. The normally open relay contacts are in parallel with your existing button for Sport mode.

Ron
 

MisterBill2

Joined Jan 23, 2018
12,399
Simulating the start can be done by monitoring the start motor control command. When start is released and the ignition system is on then the engine is running. That is the condition to start the one second, non-retriggerable, timer to simulate the button press, exactly as Ron described.
The remaining problem is knowing which wires on the connector will work to duplicate the button press. Neither figure tells us that.
 

Thread Starter

hootistigglebits

Joined Jul 5, 2022
8
Well alrighty. So when you start the car the mode is similar to the various GOAT modes I mentioned. The car defaults to Comfort mode and you really want Sport mode. I assume that to be correct. With that in mind you want to simulate a button push for sport mode. So on engine start, engine running you want a delay on make for about 1 second, followed by maybe about a 1 second pulse or less simulating a button press? Would that be about it? Rather than the default mode just auto switch to the sport mode correct? So we need an engine running signal to start things and I have no clue where to get that on your vehicle. You can likely buy a "one shot" timer which will give you a one second pulse. Drive a small relay which simulates a button press. The normally open relay contacts are in parallel with your existing button for Sport mode.

Ron
You are 100% correct in your assessment.
 

Reloadron

Joined Jan 15, 2015
6,698
You are 100% correct in your assessment.
With that in mind and using the suggested engine running (after start) I would use the engine running to trigger a simple One Shot multivibrator. That will give you a single pulse of preset duration on a trigger signal. I doubt there is any current across the existing switch to be concerned with. You can generally find complete modules including 12 volt versions for automotive applications on Amazon and they are inexpensive and have a relay output making it easy to parallel with your existing switch button. That would be my best guess as to get what you want. That or keep pushing the button. :)

Ron
 

Thread Starter

hootistigglebits

Joined Jul 5, 2022
8
With that in mind and using the suggested engine running (after start) I would use the engine running to trigger a simple One Shot multivibrator. That will give you a single pulse of preset duration on a trigger signal. I doubt there is any current across the existing switch to be concerned with. You can generally find complete modules including 12 volt versions for automotive applications on Amazon and they are inexpensive and have a relay output making it easy to parallel with your existing switch button. That would be my best guess as to get what you want. That or keep pushing the button. :)

Ron
Is this what you're talking about because not much came up when I searched one shot multivibrator.
https://www.amazon.com/XLX-Regulato...sprefix=one+shot+multivibrator,aps,634&sr=1-4
 

LowQCab

Joined Nov 6, 2012
2,170
Get an "HPTuners" Software and Interface-Module package, and learn how to use it.
Then You can set the default behavior any way You like,
with zero changes to the wiring or Switches.

But what you need to do first is to "beef-up" the Transmission as much as possible,
unfortunately, much of the super-mushy Transmission behavior is mechanically "built-in".
Sometimes a "Shift-Kit" will fix some of it,
which then will allow You to actually make it act like You really want it to with the Software.
.
.
.
 
Top