re: failed car ignition

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

This is quite interesting.. The RF link from engine control unit (ECU) to 
transponder in the ignition key is a low frequency inductive link (60-100 
kHz or so..).. The coupling is usually done by a coil that surrounds the 
ignition key lock.  All the smarts is in the ECU (so you can't defeat it by 
cutting some wire in the steering column).

It is not out of the question that a TC might radiate enough energy to 
couple into this system and confuse it enough that the ECU and key can't 
run their protocol.


At 07:40 AM 7/8/2003 -0600, you wrote:
>Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><IanHelixsp-at-aol-dot-com>
>
>Hi all
>
>My previous occupation was as a technician, working for Audi/VW (18yrs).
>During the last few years we had more and more complaints about vehicles 
>refusing
>to start when parked in certain locations! After some time and processes of
>elimination I realised that this was due to r.f. interference from radio
>transmitters i.e. near the local police h.q. etc. (Also in the same areas, 
>cases of
>continuous false alarms from vehicle security systems) I have never had an
>instance of a vehicle breaking down due to this, just failing to start. I
>attributed this to the vehicle immobiliser system, which usually takes the 
>form of a
>radio transponder within the ignition key. The E.C.U. is programmed in a 'fail
>safe' mode to prevent the vehicle from breaking down once started and running.
>In other words the immobiliser's digital out-put is ignored once the engine
>is running.
>
>Cheers,
>Ian D. Liverpool U.K.