Immobilizer Options

[fast4motion]

I'm currently wiring a Link RX in an older rotary vehicle with aftermarket injection, and would like some advice on immobilizer options with the Link.

1. I'd like to wire a kill switch to a Link DI, which will prevent the engine from firing when trying to start it, but the switch input will be ignored once the engine is running (above certain rpm), so inadvertent switch operation won't shut the engine off while driving. I'm sure I've read in the past that this can be done on the G4X, but want to confirm it can also be done on the older G4?

2. I'm also wiring in a GPS tracker, with remote immobilizer/shut-down function via phone app if the vehicle is stolen. The instructions say to only connect it to a starter relay to prevent engine start (so it doesn't create a crash/safety risk by shutting off the engine while driving if it was connected to the Ignition relay), but this isn't much use while the vehicle is being driven away by thieves. So, in tandem with the starter relay, I'd also like to wire it to a Link DI so it goes into limp mode or engages a soft rev limiter or similar. Ideally, I'd like it to then shut the engine off after about 30 seconds of limp mode, so there's time to pull over safely and then the engine won't restart. Is this possible to have the Link shut down the engine after a set period of limp mode?

Also keen to hear opinions on the pros and cons of shutting the engine down remotely, versus just remotely disabling the starter motor (which still won't prevent it being push started, or a screwdriver across the starter terminals).

 

ETA: Just realised this might be the wrong forum, and maybe it should be in the Historic G4 forum, so please move if appropriate.

Edited April 14 by fast4motion

[Adamw]

I havent tested this but the example below should give you something similar to what you describe.  The kill switch is wired to DI4 and the tracker to DI3.  

Virtual aux 1 is used for the "kill conditions" - If the engine isn't running and either the kill switch or tracker inputs are active then VA1 will be true.  When VA1 is true the GP RPM limit will be using the bottom row of the table - i.e RPM limit is 0, so the engine wont start.  

If the tracker/DI3 is activated when the engine is running then that will start timer 1 running, the GP limit table will be working in the top row which has the RPM limit reducing to 0 over 40 seconds.  

 

 

 

 

[fast4motion]

Thanks Adam, that's even better than I'd planned. The decreasing RPM's could make a thief think that they're running out of fuel, and not look for an immobiliser. If the relay/fuse box wasn't already maxxed out, I could even wire a relay so the fuel gauge drops to empty when the immobiliser is activated.

Could you please confirm a few things for me regarding the older G4 Link capabilities before I finalise and begin installing the wiring loom. I've been playing with PC Link G4 (not connected to the ECU), and some of the set-up is quite a bit different to the G4X.

1. I want to use Aux3 for the CEL light, but also want it to be the Oil Pressure light (switched by the Link). I know it's possible on a G4X, but can I do this with the G4, presumably using a Virtual Aux for the Oil Pressure, and have it output a constant ground on Aux3 when oil pressure is low?

2. I have a switch wired to DI1 to turn on the radiator fan manually, in addition to the Link controlling the fan. The car has a Line Locker which I want to wire to DI2, and have the Link turn the radiator fan on when the Line Locker is engaged. So 12V on DI1 turns the fan on, or 12V on DI2 also turns the fan on, and fan is also temp controlled. Is this possible? Looking at PC Link G4 it appears to have 3 Virtual Aux Outputs, and I'm worried about having too many overlapping/conflicting inputs and outputs (kill switch, oil pressure/CEL, fan switch, linelock-fan switch).

3. I planned on wiring and configuring Temp 1 as ECT, Temp 2 as IAT, and AN Volt 4 as Oil Temp with a pull-up resistor. However the car has an aftermarket CAN digital display, and I just read this thread on the G4+:

I prefer to wire tuning related sensors like IAT to dedicated AN Temp inputs. Should I continue wiring as planned, or should I swap Oil Temp and IAT inputs to make it easier to display the Oil Temp on the digital display? Does it matter either way?

Thanks.