Alex
Please expound, or post a link to a site which explains this in more detail, please.
Thanks in advance.
It’s something which actually happens fairly infrequently, but can explain a lot of “mysterious” electrical problems in cars. (Also happens to be the area I work in, so forgive any slightly anecdotal evidence!).
In simple terms, any electrically noisy item, or intentional transmitter (such as a mobile phone) will have an electromagenetic field surrounding it during operation.
This field has the potential to induce unwanted little currents and voltages that can upset the operation of the victim items exposed to that field.
There is evidence of certain cars stalling when driving past high power transmitters, Airbags exploding when a mobile rings in the car, instrument clusters going bonkers near airport radar. That sort of thing.
Generally, manufacturers such as Ford (and all members of Ford group, Volvo,Jag, Aston etc) perform testing to eliminate most of the effects as far as possible. You can never test for every eventuality though and sometimes a unique combination of circumstances leads to an EMC event occuring.
Generally, Lotus have never bothered too much with testing and tend to rely on work done by their suppliers. Lotus still have to meet the minimum requirements for “e” marking obviously.
It’s possible (I’m suggesting) that the immobiliser was upset (armed effectively) by some electrical event in the car, be it a voltage spike, power dropout (from a vibrating connector or “chattering” relay), or a radiated field from a phone, other on board item, or a transmitter it was passing. A simple reset cured it, with no other effects. It may never happen again, or it may be something as simple as re-routing an element of the wiring loom. If it keeps happening, the first suspect of course would be the immobiliser box itself, from a normal reliability perspective.
As I say, a lot of work goes on to prevent this sort of thing occuring, but it can and does still happen, like all other reliability issues…
Hope this helps.
Alex.