Newbee here - first post.
Apologies if this is in the wrong section (or is one of those frequently covered subjects) but I can't find a definitive answer to my questions.
I'm about to buy a V4 MJL and fit it in an old Mini. It's notoriously difficult to stop people stealing Minis due to their lack of decent locks and very simple electronics, it seems an ideal opportunity to incorporate the MJL into an anti theft system. To do this I need answers to a few questions that I have. Does anyone know the answers to the following?
Maximum current consumption of a V4 MJL?
If I stop the PIP signal reaching the EDIS will this prevent the system from working? (I understand if I cut the SAW signal the EDIS just goes into limp home mode).
If cutting the PIP signal will not stop the EDIS what other signal can I interrupt (apart from the obvious power to the EDIS or MJL)?
Megajolt as an immobiliser?
Moderators: JeffC, rdoherty, stieg, brentp
Hi and welcome,
Yes, the engine will run on EDIS alone. If disconnected from the MJLJ it will run at a fixed 10 degrees BTDC, which will allow it to run well enough to drive away.
Your best bet is to have a hidden switch disable various critical components such as the fuel pump or cut power to the EDIS module. Multiple different switches offer more security.
Of course, it's simply a deterrent- if a thief is determined and has time they will be able to get it regardless.
The MJLJ consumes < 1 amp.
Yes, the engine will run on EDIS alone. If disconnected from the MJLJ it will run at a fixed 10 degrees BTDC, which will allow it to run well enough to drive away.
Your best bet is to have a hidden switch disable various critical components such as the fuel pump or cut power to the EDIS module. Multiple different switches offer more security.
Of course, it's simply a deterrent- if a thief is determined and has time they will be able to get it regardless.
The MJLJ consumes < 1 amp.
Rats, I hadn't realised that the car would still run without the MJL powered up at all! Bang goes my first idea of an immobiliser.brentp wrote:Hi and welcome,
Yes, the engine will run on EDIS alone. If disconnected from the MJLJ it will run at a fixed 10 degrees BTDC, which will allow it to run well enough to drive away.
Looks like it's the fuel pump and the EDIS on the immobiliser circuit then.brentp wrote:Your best bet is to have a hidden switch disable various critical components such as the fuel pump or cut power to the EDIS module. Multiple different switches offer more security.
Vermin, all of them.brentp wrote:Of course, it's simply a deterrent- if a thief is determined and has time they will be able to get it regardless.
The MJLJ consumes < 1 amp.
Many thanks for the information.
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Spockie-Tech
- Posts: 152
- Joined: Wed Jan 02, 2008 12:52 pm
- Location: Melbourne, Australia
I had a thought of inserting a small relay inline with the VR sensor cable in a sealed box somewhere out of sight.
No VR sensor signal, no sparky..
Bonus points - Put a small Micro (picaxe maybe) or timer widget in the box that switches the relay on and off at short intervals to allow the engine to start briefly, then die again, and requires a serial datastream, one-wire button ID or some non-trivial ID signal to enable the VR sensor. thats probably beyond the capabilities of your average joe though.
No VR sensor signal, no sparky..
Bonus points - Put a small Micro (picaxe maybe) or timer widget in the box that switches the relay on and off at short intervals to allow the engine to start briefly, then die again, and requires a serial datastream, one-wire button ID or some non-trivial ID signal to enable the VR sensor. thats probably beyond the capabilities of your average joe though.