Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   Grand Cherokee - WK (http://www.jeepgarage.org/f5/)
-   -   Key not working (http://www.jeepgarage.org/f5/key-not-working-18360.html)

Dusan 02-03-2011 12:29 PM

Key not working
 
A while ago my key - integrated key fob 5 buttons died (2008 WK). I tought the batteries died and because I was in a hurry I just grabbed the spare key, replaced the non working one wich I tossed in a drawer. Yesterday I tried to ressurect it, replaced the battery with a new one, and still did not work. I pressed every button to no effect. I craked it open, cleaned contacts, pcb, measured battery voltage, made sure it makes good contact, but still nothing. I noticed that on the PCB there are a loop antenna and a SMD one. I think one is for 434MHz - remote functionality and the other is for communicating with the Ignition ECU module when the key is inserted.
This morning I opened the car with the working key, and I tried cranking with the non working key - it worked! I tried the buttons, they are working too!

Is the module reprogramming the key each time it's inserted? It may explain what happened: The voltage was too low to reliably program it and it failed to work as a remote even when the batteries were changed . Once inserted it recognized the right code and reprogrammed this time right because the voltage was up again.
Is my thinking valid or something else is going on, my key is failing? Can somebody explain what is going on with the key? I'm affraid It will just quit working again.

SvenskaJeepGuy 02-03-2011 05:33 PM

Re: Key not working
 
if the alarm is going off from it - you have to remove the negative terminal on the car battery for like 5 minutes for it to work again.
if nada happens - then the inside of the remote is messed up

ny450es 02-05-2011 08:41 AM

Re: Key not working
 
Quote:

Originally Posted by Dusan (Post 347461)
A while ago my key - integrated key fob 5 buttons died (2008 WK). I tought the batteries died and because I was in a hurry I just grabbed the spare key, replaced the non working one wich I tossed in a drawer. Yesterday I tried to ressurect it, replaced the battery with a new one, and still did not work. I pressed every button to no effect. I craked it open, cleaned contacts, pcb, measured battery voltage, made sure it makes good contact, but still nothing. I noticed that on the PCB there are a loop antenna and a SMD one. I think one is for 434MHz - remote functionality and the other is for communicating with the Ignition ECU module when the key is inserted.
This morning I opened the car with the working key, and I tried cranking with the non working key - it worked! I tried the buttons, they are working too!

Is the module reprogramming the key each time it's inserted? It may explain what happened: The voltage was too low to reliably program it and it failed to work as a remote even when the batteries were changed . Once inserted it recognized the right code and reprogrammed this time right because the voltage was up again.
Is my thinking valid or something else is going on, my key is failing? Can somebody explain what is going on with the key? I'm affraid It will just quit working again.

my key stopped working and it wasn't a year old yet. turned out to be a bad solder connection. had a friend solder it and was workin for a while. now its bad again so i'm taking it to the dealer. a jeep tech had told me the keys were going bad due to static electricity. really don't believe that one as the internals are covered by plastic and rubber. and static electricity would fry the chips and never work again(someone correct me if i'm wrong). have someone resolder your battery terminals to the board...it's easy to do.


All times are GMT -5. The time now is 07:13 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community