Setting up engine immobilizer function

[Wildt267]

I live in a high theft area.  Factory ecu and previous aftermarket had an engine immobilizer.  I'd like to set something similar up in the g4x.  I've checked the forums and the built in help file but didn't find any relevant information. Instead of adding a physical kill switch that a potential thief might look for I was thinking about repurposing one of the factory functions instead.  I'm just not quite sure what the best way to do it is.  I was thinking ideally i want to ecu to look at the input just long enough to start the motor and then completely ignore it while engine is running such that i don't bump it during vehicle operation and shut the motor off mid drive.I was wondering if Adam had any suggestions for this.

[Vaughan]

What vehicle do you have? you could set up a gp output that controls one of the virtual aux's and is active when the immobiliser input is off and the engine speed is less than 400rpm and then feed that virtual aux into the anti theft input or into the stop switch input either of which will kill the engine. The use of the gp output logic means that it will only prevent you from starting the engine but once the engine is started as long as you don't dip below 400rpm it won't kill it. You can also use the on delay setting so that it can deal with short dips below the specified engine speed before killing it.

[Wildt267]

It is a 2006 Usdm Subaru Sti using the 104x plug in.

 

[Vaughan]

2 hours ago, Wildt267 said:

It is a 2006 Usdm Subaru Sti using the 104x plug in.

Yeah that one doesn't have CAN based anti theft from factory. You are going to need to have some form of input, one thing I have considered in the past but never looked into in depth would be a NFC tag and a reader that sends something out over CAN. Otherwise just a push button or switch which can include any of the factory switches if you wire them to the ECU.

[Wildt267]

I was actually considering using the nfc approach as well. Your suggestion for using a virtual output was very helpful. I haven’t utilized those yet but I’ll figure it out. Thank you for the help

[Adamw]

If your car has cruise control you could set up something like "hold the set button and brake pedal together for more than 5 seconds" to disarm the antitheft, if it doesn't have cruise you could do something like throttle pedal >50% and brake pedal together for more than *sec.  I would also set up something like the CE light to flash when antitheft is active so you know when you have successfully met the conditions.

[Wildt267]

Those are fantastic ideas, thank you very much.  I'll definitely implement them.

[koracing]

On 6/7/2023 at 9:02 PM, Adamw said:

If your car has cruise control you could set up something like "hold the set button and brake pedal together for more than 5 seconds" to disarm the antitheft, if it doesn't have cruise you could do something like throttle pedal >50% and brake pedal together for more than *sec.  I would also set up something like the CE light to flash when antitheft is active so you know when you have successfully met the conditions.

I've often considered doing this and suggested it to customers after having one customer's car get stolen years ago on an ecu that did not have the ability to do some of these more advanced functional lockouts.  The scene on how to start the vehicle in MadMax Fury road with sequence of switches comes to mind. 

How would you theoretically set up the CE light to flash while active - then go steady when inactive?  Would this also be able to work with standard fault code functions that may exist when it powers up (say due to a faulty sensor)?

[Wildt267]

I’m in the middle of implementing the suggestions. I’ve got the anti theft digital input set to my virtual aux1. Virtual aux 1’s function Is set to off/on.

I have a gp output set to the virt aux.

I have 2 parameters set but I don’t see how to get the successful trigger of the conditions to output to the check engine light, what am I missing?

Until you said something I didn’t know you could use it for anything other than the Link displaying trouble codes. I also previously tried to get it to act as a knock light. I would be very happy if it could use it to indicate a trouble code, and flash intermittently when encountering a certain knock threshold and to confirm when the anti theft conditions are met. Is that possible?

 

 

[Vaughan]

To make the CE light on the dash do more than just the standard CE light functionality you will want to set the CE Light output to another Virtual Aux and set up a gp output to control the actual Aux Output that is connected to the light in the dash and then use that gp output to either output the state of the CE Light virtual Aux or your preferred output to indicate immobiliser state.

 

[Adamw]

1 hour ago, Wildt267 said:

I have 2 parameters set but I don’t see how to get the successful trigger of the conditions to output to the check engine light, what am I missing?

Here is an example.  I have a GP output that will become true when the both the brake has been active and the TPS has been > 60% for 5seconds.  The 3rd condition "OR virt aux 8 = active" is used to latch it on once conditions are met (ie you dont want it to return to false/off as soon as you take your foot off the brake).  The catch with this logic is it works backwards compared to what we what - we actually want to turn off antitheft after 5 sec, not turn it on.  And I couldn't see a nice way to do that in the GP output - possibly I just need more coffee to see it.  So anyhow I used a mathblock to invert the logic, then we use that mathblock to turn the antitheft function on/off:

  

 

 

On 6/13/2023 at 4:56 AM, koracing said:

How would you theoretically set up the CE light to flash while active - then go steady when inactive?  Would this also be able to work with standard fault code functions that may exist when it powers up (say due to a faulty sensor)?

1 hour ago, Wildt267 said:

Until you said something I didn’t know you could use it for anything other than the Link displaying trouble codes. I also previously tried to get it to act as a knock light.

There are many ways you can do stuff like this, often it is hard to think through all of the logic in your head prior to setting it up, so I find it easier to sit in the car, set up a blank page in PC link displaying the parameters and statuses you are working with and work through one step of the logic at a time.  An example below to hopefully answer both of your questions, or at least give some direction.

Lets say I want the CE Light to flash fast when the Antitheft is active, and switch over to normal CE light functionality once antitheft is off.

First I need to generate the flash.  We can use a GP output on delay/off delay to achieve this.  This GP output will make virtual aux 1 flash on/off when the antitheft status is active:

 

CE Light output is assigned to a virtual aux rather than the real output that is connected to the lamp:

 

Now we need some logic to switch between our lamp acting on the antitheft flash virtual aux or the CE Light virtual aux.  I really needed more conditions than a GP output can do so I used a math block to achieve this.  The equation (a&c)|(b&!c) means the math book will be true when (a AND c are true) ie antitheft is active and the flash is in the "on" period), OR (b is true and c is not true), ie CE light is on and antitheft is not.  The result of this math block will be a 1 when we want the dash lamp on and a 0 when the dash light should be off:

 

 

Now we can control the dash lamp that is connected to aux 3 using the result of math block:

 

 

  

  

[Wildt267]

Thank you gentleman. This is all very helpful.

[dx4picco]

On 6/14/2023 at 4:36 AM, Adamw said:

Here is an example.  I have a GP output that will become true when the both the brake has been active and the TPS has been > 60% for 5seconds.  The 3rd condition "OR virt aux 8 = active" is used to latch it on once conditions are met (ie you dont want it to return to false/off as soon as you take your foot off the brake).  The catch with this logic is it works backwards compared to what we what - we actually want to turn off antitheft after 5 sec, not turn it on.  And I couldn't see a nice way to do that in the GP output - possibly I just need more coffee to see it.  So anyhow I used a mathblock to invert the logic, then we use that mathblock to turn the antitheft function on/off:

  

 

 

There are many ways you can do stuff like this, often it is hard to think through all of the logic in your head prior to setting it up, so I find it easier to sit in the car, set up a blank page in PC link displaying the parameters and statuses you are working with and work through one step of the logic at a time.  An example below to hopefully answer both of your questions, or at least give some direction.

Lets say I want the CE Light to flash fast when the Antitheft is active, and switch over to normal CE light functionality once antitheft is off.

First I need to generate the flash.  We can use a GP output on delay/off delay to achieve this.  This GP output will make virtual aux 1 flash on/off when the antitheft status is active:

 

CE Light output is assigned to a virtual aux rather than the real output that is connected to the lamp:

 

Now we need some logic to switch between our lamp acting on the antitheft flash virtual aux or the CE Light virtual aux.  I really needed more conditions than a GP output can do so I used a math block to achieve this.  The equation (a&c)|(b&!c) means the math book will be true when (a AND c are true) ie antitheft is active and the flash is in the "on" period), OR (b is true and c is not true), ie CE light is on and antitheft is not.  The result of this math block will be a 1 when we want the dash lamp on and a 0 when the dash light should be off:

 

 

Now we can control the dash lamp that is connected to aux 3 using the result of math block:

 

 

  

  

work like a treat.

I added an extra condition with another virtual aux.