This thing is apparently just a general pain in the butt.

With the exception of the communications with the ECU for immobilization, it looks like any moderately priced alarm/keyless entry system could drop right in and do the same job better. That also lets you get around needing to get a LR dealer to program new fobs.

What happens if you remove it? Does the ECU need to talk to this thing? Has anyone tried?

If it needs to talk to the ECU, I'm going to hook up a logic analyzer and see what it's sending. If I can get that, I can program a small microprocessor to handle that.

 

see https://landroverforums.com/forum/di...-bypass-46728/

and the RAVE set of shop and electrical manuals.

 

The "Spider" is not present in 1997 and later cars, so that doesn't help.

I've looked at all of the manuals. I know how it's connected. A Viper 350 could handle everything except the ECU connection.

If I take the thing out and replace it with a Viper 350, and leve the ECU connection hanging, what will happen?

 

I suspect no problem, as immobilzation only happens when the vehicle is armed and a new system would not be telling the ECU that. You may have to deal with the driver door arm/disarm signal, and interface from alarm to central locking.

From the RAVE:

(Z163).


So as long as you don't need a mobilise signal you would be OK. But if ECU woke up and decided it wanted to be sure it was still in the same truck, then what? Maybe test with simulating dead battery, jump from another vehicle., etc; as part of testing.

 

Well, I guess I'll find out.

 

I'm intrigued, please keep us updated with your progress. There are probably many Rover drivers ("Roverers?") would would be interested in doing this also.

 

I have a few thoughts, but I probably won't get to check them out for a few weeks.

1) Monitor the line between the ECM and the Theft Unit with a logic analyzer to see when it communicates and what it sends. If it's a rolling code or something similar, then it's going to have to stay.

2) Transfer all of the I/O except the connection to the ECM from the theft unit to a Viper 350. connect the key input from the Theft unit to the unlock or an Aux signal from the VIper to the theft unit. Since the theft unit will no longer get any signal from any of the alarm outputs, it should never tell the ECM to disable (in theory).

3) If the signal from the theft unit is repetitive for disable & enable, I'll program a small micro to do that job, and ALWAYS have it send an enable any time the viper unlocks the car, and NEVER send a disable. The viper handles the starting disable itself, and in my opinion, that's all you need.

I'm taking a look at all of the modules in the vehicle. As time goes on, the dealers are going to stop supporting some of this stuff, and some electronic parts may become unavailable. I'd also like to keep the maintenance cost on this thing down.

 

any update on this? Im very interested to see how how this panns out

 

Not very much so far. I've worked out the circuit, but need to hook up to my trucks systems to read the signal.

I've drawn up a complete schematic of the circuitry in the alarm system, and outside of the immobilizer function for the ECU, the only thing that won't work with the Viper is the door key disabling of the alarm system. I may add a little bit of circuitry to the micro board to handle that.

I was hoping to be able to hack into the processor in the alarm system and learn how to talk to it, but that hasn't been going well. I also tried getting a matched set of ECU and Alarm to talk to each other, but apparently I need most of the truck wiring to get it to work, so that takes me back to waiting for a good day outdoors. :-)

 

I tried unplugging the alarm unit. It wouldn't start. Plugged it back in and it started fine.