RFID Fob Anti-Theft Install (1 Viewer)

[SmokingRocks]

I'm building a client's vehicle and he wanted an engine immobilizer installed but didn't want it to be one of the typical Cobra-style units. After searching around on amazon I found this RFID system. Since it was so cheap I bought 3 units. Once they arrived I ripped into one of the units to see if I could trust the build quality and I was decently impressed, they consist of a basic solid state logic board that ties into a simple relay triggered by the presence of the RFID fob within the vicinity. The biggest concern is how well the logic board holds up, but that's what a bypass switch is for.

So with the client's approval, I installed the unit on his rig and it works amazingly well for how simple it is. I intercepted the IGSW input into the ECU for the RFID Module to control and powered the module off the constant BATT and E1 ground source for the ECU. The beeper on the module was super abrasive so I cut that out and replaced it with a dash-mounted LED that blinks a warning sequence when the fob is no longer detected before shutting down. Lastly, I installed a hidden bypass switch that just reestablishes the original pathway of the IGSW circuit to the ECU in the event this thing craps out.

But as of now, I'm very impressed with this module. It's so simple and versatile that it could be set up for a ton of different uses, one that comes to mind is auto-unlock & auto-locking.

Here's the wiring diagram

My neighbor stopped in while I was in the middle of this and I'm pretty sure he thought I was making a bomb or something

 

[sjpitts]

I think that is really a cool idea. Anything to make these things harder to steal. Any idea how much current it draws just sitting there? My 80 sits more than it moves.

And I wonder if you could use it with Huddexpo's Starter kill switch wiring and if that would make an easier install.

 

[canman]

i’m certainly no expert, and not even sure what an RFID FOB is, but I thought I would mention something I just learned. Was recently speaking to the owner of an automotive paint store who happens to own an LX570, and whose daughter owns a RX350. Hers was stolen, and within a few month period he told me 120 Lexus vehicles were stolen in the city. Apparently thieves intercept the signal being transmitted to and from the FOB/ vehicle, duplicate it and then they can start the car. They were even stealing brand new cars from dealer lots using this technique. Don’t think it would be the same for the 80 as it still physically needs a key, but I thought I would mention it as I had never heard of this before.

 

[sjpitts]

A modern key FOB can unlock the doors and start the car. I think in this case the detection of the FOB just turns off the kill switch. And the unit would not even be on and try and detect the FOB until the key was turned on. If I understand what SmokingRocks is doing here.

 

[SmokingRocks]

no the control board needs constant power to retain the memory of the programmed fobs. Your ECU has a constant power source so it can retain any stored trouble codes, same with the cruise control ECU, trans ECU (93-94) and your radio has one too to remember settings and preset stations. I haven't measured the draw of this device but I doubt its anything over 0.03ma which is virtually nothing.

The constant power in is ONLY for the logic board / receiver, the relay is powered by the positive source that you are trying to control (yellow wire), so I have it set up that the IGSW circuit is that input and it will only make the relay 'ready' when the ignition switch is turned on.

 

[thecapedcapper]

Clean looking install, and nice diagram. I have to ask though - why do this at the ECU ? Couldn't you have intercepted the IGSW wire under the dash or something like that?

 

[SmokingRocks]

The first place thieves often look for an immobilizer is under the dash in the driver's footwell, and there are many documented cases where thieves were able to defeat the immobilizer because they found it and steel the car. I wanted this to be hidden.

There are a million ways and locations in which this could be wired in, you could intercept the fuel pump circuit, ignition circuit, afm/maf circuit etc etc etc. I chose to mount it at the ECU because it's already out for the engine rebuild, I could install most of it on my bench and it would be a very hidden module.

 

[Stylo07]

I'm building a client's vehicle and he wanted an engine immobilizer installed but didn't want it to be one of the typical Cobra-style units. After searching around on amazon I found this RFID system. Since it was so cheap I bought 3 units. Once they arrived I ripped into one of the units to see if I could trust the build quality and I was decently impressed, they consist of a basic solid state logic board that ties into a simple relay triggered by the presence of the RFID fob within the vicinity. The biggest concern is how well the logic board holds up, but that's what a bypass switch is for.

So with the client's approval, I installed the unit on his rig and it works amazingly well for how simple it is. I intercepted the IGSW input into the ECU for the RFID Module to control and powered the module off the constant BATT and E1 ground source for the ECU. The beeper on the module was super abrasive so I cut that out and replaced it with a dash-mounted LED that blinks a warning sequence when the fob is no longer detected before shutting down. Lastly, I installed a hidden bypass switch that just reestablishes the original pathway of the IGSW circuit to the ECU in the event this thing craps out.

But as of now, I'm very impressed with this module. It's so simple and versatile that it could be set up for a ton of different uses, one that comes to mind is auto-unlock & auto-locking.

Here's the wiring diagram
View attachment 3126419

My neighbor stopped in while I was in the middle of this and I'm pretty sure he thought I was making a bomb or something
View attachment 3126422View attachment 3126421

I didn’t understand a word you just said.