Immobilizer Bypass Module

Discussion in 'SN95 4.6L Mustang Tech' started by joey_corleone82, May 24, 2006.

  1. I had a viper 791 alarm put in. The shop used a DEI 556U bypass module, but it has given me problems from day one and they can't figure it out. What happens is once in a while intermittantly when I actually put the key in the starter to go start it, it does not read right, resulting in the theft light blinking fast and a crank/no start condition. If you play with it for a few times it works, and the remote start works.

    I was under the impression that the bypass should not have effected the factory system when you use the key, only on remote start, so either they have something wired wrong, or it is the wrong module. Does anybody know any information about this?

    I have a 2001 GT Convertible. Thanks you much!
  2. Best thing to do would be to have that f'n aftermarket alarm system removed in my opinion. You can probably find some dumbass to buy it on eBay.
  3. hrmm..most times the bypass is only needed for autostart. fords anti theft is good for stoping theifs from starting/running the car. an aftermarket alarm would be good to protect stuff on the interior.

    if you ditched the bypass and any ignition kill stuff from the aftermarket alarm you should be fine
  4. Some places take the chip out of your key and stick it under the steering wheel column.
  5. I have two problems with alrams and remote starts one is in general and one is for PATS equiped cars..

    1. the hacks that install these alarms.. only the guys that wire up police cars are bigger hacks than these guys.. any wirring F-up you can think of I have seen atleast 100 times from these people.

    2. the key that they put under the column makes the pats system usless. if they can turn the lock cylinder they can take your car if you have remote start.
  6. The reason I had this system put in is because 1 week after I had my brand new stang on the road it was broken into and vandalized....stole both airbags right in a lit parking lot at work...and lets just say this company is a major global corporation. You are right though, I can't believe that the people that install these...I've had more problems and it's like they are just guessing on what to do. Not very reassuring. I love the alarm and the remote start, my only regretis not doing my homework on a shop with good people first.
  7. I've got the 791XV as well, along with the remote start, and the 556U isn't up inside the dash right now. I think since it's a manual, the installer took the ignition ring out when he hooked up my aux trunk switch. Anywho...the 556U isn't activated unless it gets a voltage from the brain saying that it's about to remote start. I once had the same problem you speak of, but I can't remember what it was. Try resetting the ECU by disconnecting the battery for a while. I think that's the only thing I did.