reign

I've been having trouble with the viper remote start on my tC. Whenever I initiate the remote start, the engine cranks but that's it. It also still only cranks when I have the key in the iginition. I read that the part of the tC's immobilizer that checks the key only activates when the key's in the ignition or turned into the ignition position. Do I need to hook up the keysense wire for my 555U to work correctly? Also, if I do, what part of the alarm do I need to hook it up to?

Thanks

Harmonic_tC

Either you dont have the 2nd starter wire hooked up, the tach hooked up, tach programmed, swithched it to voltage sensing.

Did you install it yourself?

If you had a shop do it then take it back there because it doesnt sound like installed it correctly

reign

I did install it myself. This is my third or fourth alarm install, but the only vehicle that had an immobilizer. I do have the second starter wire hooked up through a relay. The relay is powered off of the same wire that powers the 555U. The RPM wire is connected to the pin in the top connector at the ECU. I tried switching it to voltage sensing, and I've also tried low and high voltage sensing. Also tried different crank times. I think the problem is with the immobilizer because the fuel pump does not switch on. I've tested all of my soldered wires with an ohmmeter and double/triple/quadruple checked all of the connections. Only thing that I can really think of is that keysense wire. I'm about stumped.

Shoelesscraig

Well, the first thing that I notice is that you said 555U. If thats a typo and you meant 556U then ok, but if you did mean 555U, then there's your problem, the 555U does not work on a Scion tC. This is according to Directechs.

I have remote start on my tC and I'm using the 556U and it works fine. I DID NOT hook up the keysense wire to answer your question. If all your other connections are right, then I would say that you need the 556U. This is the one that requires you to put one of the keys into the module itself and leave it there. I put in one of the keys that has the factory keyless stuff on it. I carry around the valet key b/c it is smaller and b/c my alarm (Viper 791) has the keyless entry built in.

Also, make sure that you do not have the accy & ignition wires backwards. Thats a common mistake, see it all the time. (Not trying to insult your intelligence, haha, but it is a common mistake, I did it myself when I first started). The ignition wires will still have voltage when the starter is turning over trying to crank the car. The accy wire will lose voltage while the starter is trying to crank the car, and then resume voltage once the key is released. This is why the radio goes off when you are trying to start the car. If you have these 2 wires backwards, it will cause the problem you are describing too, but I still think you need the 556U. That is more than likely your problem!

Anyways, hope this helps. If you have any questions. let me know, I'll help if I can! Good luck with it!!!

Harmonic_tC

555U and the 556U is the same thing. the 556U is just a newer model, so that should have no effect at all.

reign

I know one of the upgrades between 555U and 556U has something to do with keysense. I'll double check all of my wires again, but I do believe they're all going to the right place.

I have Pink going to Blue on the ignition harness and Pink/White going to Yellow.

I will look into changing out the 555U with a 556U and see if that fixes my problem

Thanks for the help guys.

Shoelesscraig

I stand corrected! After I posted that, I realized that I'd never used a 555U, and I thought, "hmmm, maybe its an older version of something"...haha, oh well. Ok with that out of the way...

If the car still wont start with the key in the ignition, then it has nothing to do with the 555U, not sure why I didnt see that before...if the keys in, then it should start...if its not, then it has to be something else. Not to sound dumb or anything, but you did "learn" or "program" the tach wire, right?? As in, start the car with the key, within a couple of seconds press and hold the valet button and wait for the LED to light...right?? Just checking...

If it wont learn the tach wire, then maybe you should try moving the tach wire to the diagnostic connector under the dash, drivers side...black wire, pin 9...thats where I have mine anyways...Good luck man, if this isnt the problem, I have no idea what it could be...bad alarm maybe?? Like I said, it cant be the bypass module if the key is in the ignition and it still wont start...And like you said, you have the ignition wires hooked up correctly...

reign

Hmm... It seems to learn the tach ok. The LED comes on and stays solid just a moment after I hold down the button. I'm going to take a look over everything tomorrow, maybe try moving the tach wire. I'll post here once I have any updates.

captain_co

I just installed the Viper 791XV on my car with a friend this weekend and I haven't had any problems with mine starting. Make sure that you have a key hidden somewhere in the car with a transmitter on it because the ignition looks for the signal coming from the key.

stCx86

so we definitely have to place a key some where in the car?? but what about the spare, that key doesn't have the signal transmitter on it does it? so no matter what with the viper alarm with remote start, we have to sacrafice one of our keys in order for the alarm to operate properly with the remote start. i'm thinking of buying the viper so any advice/tips/experiences would be greatly appreciated! thanks in advance.

tweetertc

yeah... our cars come with an antitheft device ... there is basically a small chip in the key that without it being in the ignition the car will not start... most people give up their spare grey key... and its all good... and the alarm would function just fine withour a key in the car.... its just if you get the remote start it wont work...

stCx86

so our spare key has a chip inside of it too??? (the key with no buttons on it just so we got that clear). does it HAVE to be in the ignition?? or can it just be hidden anywhere inside the car??

TongMan

I have the 771 xv Viper and my remote start works perfectly. I don't know if it'll work with Manual transmission tC's though.