Engine Management And Security

[Guest clwydian]

Ok, just suppose I was parked 10feet from an antenna radiating 100watts on 14MHz - and I opened my bonnet - IS IT conceivable that I could spoil the settings memories in the engine management system/security (key) module??

 

Hypothetically of course. :(

 

Carl

[Guest SA Intruder]

Depends on EMC protection measures on vehicle.

 

I suspect it won't affect much....but I wouldn't try it...the radio and the remote won't like it...they are expecting microvolts of RF. Not volts.

[ALARM MAN]

Hi mate looks like you had a lock out imagine your in a room next to some one and you chatting

Then a big big crowd comes in next to you and start shouting and getting loud.

suprisingley you can not hear your mate

That is what happens when you park too close to a transmitter it gives out a big blast and your car cannot receive your transmitter

 

Supermarkets are the worst for it

 

Ian

[kevinp]

Sounds like you maybe living close to a radio ham if you do really mean 14MHz. (although 100 feet to the car seems pretty close!). From my many years of EMC testing, I would be surprised if you have a problem at this frequency but you never know - it is more usual at VHF & UHF requencies.

Kevin

[Guest clwydian]

Ok, forget the hypothetical bit. I was parked just a little away from a ham running 100w at 14MHz and then 50MHz in a pub car park. (Im a ham too

so no jokes k?) Anyway - the central remote locking was fine (so we arent talking

radio desensitisation) but after everyone had gone home, my car nolonger recognised my car key (chipwise)- so no starting :unsure:

 

We are talking three days and 200pounds to fix it.....

 

Im anxious not to repeat it. But I have noidea what actually failed and

since the diagnostics were down on the car too...ntiehr has the dealer who

replaced the 'secuirty module' and reprogrammed something....?

[Guest yurir]

Hi Clwydian,

 

Just came across this as I was browsing through all the topics.

 

The electronics in the car should be immune to a field strength of the order of at least 50V/m; I know VW have 200V/m as their ideal, but how well they're achieving it ...???

 

Anyway, radiating from a unity gain antenna, the approx. field strength is

 

E = [ (30*P)^0.5 ] / d

 

which would give you about 18V/m at 3m from 100W.

 

So I wouldn't think that would be the cause of the problem; at least to the car.

 

However, I don't know if the PATs keys have the same inmmunity, given that they have to derive their power from an RF signal i.e they HAVE to be more susceptible.

 

Best wishes,

Yuri.

[Sher]

I seem to remember quite a few people at one stage having problems at the waiting section at Calais perhaps 10 years ago?

Too much interference from radios/ radarwas spoken of as a possibility.

The batteries in the fobs are small and seem to last forever so the Transmitted power can only be mWs and could so easily be drowned out.

Also don't codes sometimes cycle on from one use to the next to prevent them being grabbed?? opr was this a recipe for disaster and dropped?