1. Attachments are working again! Check out this thread for more details and to report any other bugs.

immobilizer question

Discussion in 'Generation 1 Prius Discussion' started by carangil, Sep 1, 2014.

  1. carangil

    carangil Junior Member

    Joined:
    Jan 19, 2012
    9
    3
    0
    Location:
    Sunnyvale
    Vehicle:
    2001 Prius
    Model:
    N/A
    Does the immobilizer only check the key at engine start, or is the check continuous/periodic as the engine is running?

    I have a 2001 Prius and my wife has a 2001 Highlander. I only have 1 master key remaining for the Prius, and both cars use the same transponder type. I had a plain (metal, no transponder) copy made for the Prius, and it turns all the locks just fine. I also followed the master key programming steps with the metal non-transponder key in the ignition, but holding the Highlander key in close proximity to the ignition. It worked! If I have the highlander key on the keychain next to the metal spare Prius key, the Prius will start. The Highlander key is now a 'superkey,' it will start the Highlander, and it will also pacify the Prius immobilizer.

    But this is not 100%; if it doesn't sit right on the keychain, I sometimes have to hold the Highlander key a little closer to the ignition to get it to recognize. I

    My question is: is this dangerous? While driving, if the Highlander key jiggles out of range for too long, will the Prius just stall? Or is the immobilizer handshake only for starting, and once running no longer required?
     
    #1 carangil, Sep 1, 2014
  2. RobH

    RobH Senior Member

    Joined:
    Sep 18, 2006
    2,369
    981
    70
    Location:
    Sunnyvale, California
    Vehicle:
    2006 Prius
    The transponder enables the starter. So once the engine is running, the transponder is ignored.

    As long as there's only one transponder in range when you start the vehicle, there shouldn't be any problem. And if you do have a problem, just move the offending key a few inches further away.

    You might cross register the Prius key transponder on the Highlander just to have an extra key for it. It would probably work to wrap the head of the Highlander key with aluminum foil, use it in the lock, while holding the Prius key head near the switch.

    Each vehicle just has a list of transponders that it recognizes. Nobody's counting where else a transponder has been...

    This also works for Gen2 keyfob transponders (key in dash). One keyfob could be recognized on any number of vehicles.
    The remote and smartkey functions are locked to a single vehicle, but a transponder is not.
     
    #2 RobH, Sep 2, 2014
(You must log in or sign up to post here.)