Immobiliser, Fiat 500

[ciddyguy]

I spent (literally) all day yesterday pretty much researching for more info on the immobilizer and the alarm features (general features) but didn't get too far other than what was provided in England, thanks to the Thatcham organization.

Well, this morning I read more on the Thatcham site and they ARE known outside of England and many countries/companies that do alarms for the automotive field know of them and perhaps use the Thatcham criteria as the basis for their own regulations and certification if not using the Thatcham certifications/criterias outright.

And in my research yesterday, read up on the legislation (sort of) for increased penetration resistance for immobilizers on new cars sold in Canada which was put into law in 2007 which then made importing vehicles from the US illegal as the immobilizers sold here didn't fit the criteria, but was later, I think rescinded after much crying foul by citizens and politicians alike. This topic kept coming up quite often and it was NOT what I was looking for.

Anyway, still haven't found the EXACT specifications/requirements for immobilizers for the US yet (yes, did hot the NHTSA/FMVSS sites but hadn't found the exact documents I wanted regarding this) but will keep trying but in the meantime, found a clarification on the category 2 immobilizers per the Thatcham organization this morning which may explain why some of you have noted no locking steering wheel and it may be that the US is using either the same criteria or it's very close to this.

Category 2
Passenger Cars, LCV, HGV, Plant, Motorcycles
ELECTRONIC/ELECTROMECHANICAL IMMOBILISER

    * Immobiliser
      Passively set
      Isolates a minimum of two operating circuits or systems, or a minimum of one operationally relevant vehicle control unit with coded intervention


What it means is that, according to their pdf on the systems used (code 2 immobilizer) for most Fiats made since 1999 on are all software lock related and have a transponder, and the description I listed above essentially says, that the system will isolate a minimum of 2 operating circuits or systems (such as the ignition and fuel) OR a minimum of 1 operationally relevant vehicle circuit, such as the steering wheel I think with coded intervention so it may be that they choose not to use a mechanical or electromechanical locking device for the wheel after all since what they are isolating more than meets the criteria set forth by NHTSA (I read where they were able to demonstrate this and get exempted from parts marking, for at least a year anyway on the Fiat 500).

I think these days, many cars now use a semi mechanical locking pin using a solenoid or tiny servo to do the locking/unlocking actuations instead of the fully mechanical units found on older cars, meaning that many steering wheels don't necessarily lock immediately upon key removal but will once you lock the car however and the same thing is apparently used for the gearlock on automatics, thanks to the requirement of one pressing on the brake pedal to release the shifter out of park. If you have ever had to replace the lock cylinder on an older vehicle that's on the steering column, you'll know that the locking mechanism is part of the key lock tumbler assembly and on some cars, can be completely removed for repair/replacement of either the entire tumbler/ignition unit or one or the other (as in older VW's) where you CAN just replace the switch itself without having to replace the key tumbler (or vice versa).

I know many older cars used a mechanical cable to release the parking pawl on the floor shifters but that may not be as true on very recent models as more and more systems in the car go all electronic or semi electronic for all functions.