TJ immobiliser key FOB only works sometimes

[mortythejeep]

Hello guys, I need some help.! So lately my Jeep Wrangler TJ 1997 UK model has had an issue with the immobiliser key fob. It seems to work whenever it wants to and more often than not it leaves me stranded I have tried to repair the remote, but it sends a signal sometimes week or not at all. I can’t seem to find anyone that can copy the key. Is it possible to find a used one and copy it or is there any aftermarket key fob that is compatible or should I just remove immobiliser and if I do so do i just remove it or must something else be done ?

 

[Chris]

Hello guys, I need some help.! So lately my Jeep Wrangler TJ 1997 UK model has had an issue with the immobiliser key fob. It seems to work whenever it wants to and more often than not it leaves me stranded I have tried to repair the remote, but it sends a signal sometimes week or not at all. I can’t seem to find anyone that can copy the key. Is it possible to find a used one and copy it or is there any aftermarket key fob that is compatible or should I just remove immobiliser and if I do so do i just remove it or must something else be done ?

Have you checked the battery in the key FOB to start with?

 

[jscheu]

I have had the "chip" in the key fail on mine.

 

[mortythejeep]

Have you checked the battery in the key FOB to start with?

Aa yes multiple times, I replaced the metal piece that the battery sits in as it did not make proper contact

 

[mortythejeep]

I have had the "chip" in the key fail on mine.

They have told me it may be an issue on the board that’s not accessible although i do not know much about electrical boards

 

[Chris]

I'm going to guess that the key itself needs to be replaced with a new one (programmed too) at this point. That's where I'd start.

 

[mortythejeep]

I'm going to guess that the key itself needs to be replaced with a new one (programmed too) at this point. That's where I'd start.

Problem is i cant seem to find a key fob that can be programmed, they have tried to program it and it doesn’t work

 

[KennethS]

Have you checked the battery in the key FOB to start with?

I had issues with my garage door opener not working consistently. I work in an electronics failure analysis laboratory so have access to a lot of diagnostic equipment. I discovered that the “generic” coin cell batteries that I bought on Amazon had the correct 3 Volts, but could not output the current needed by the wireless chip and the voltage collapsed when the opener was activated. A new coin cell battery from the local store resolved the issue. I have experienced a similar thing with “generic” Amazon coin cell batteries for my watch as in they last around 6 months before failing.

So I say get a name brand battery from a local store and see if that resolves your issue.

 

[Chris]

I had issues with my garage door opener not working consistently. I work in an electronics failure analysis laboratory so have access to a lot of diagnostic equipment. I discovered that the “generic” coin cell batteries that I bought on Amazon had the correct 3 Volts, but could not output the current needed by the wireless chip and the voltage collapsed when the opener was activated. A new coin cell battery from the local store resolved the issue. I have experienced a similar thing with “generic” Amazon coin cell batteries for my watch as in they last around 6 months before failing.

So I say get a name brand battery from a local store and see if that resolves your issue.

That's interesting you say that. I've been having problems with the coin cell batteries in everything I use them in. Coincidently (or not) I bought them on Amazon. I guess I need to test this out for myself!

 

[mortythejeep]

thats a great point! But unfortunately i tried multiple brand name batteries, and now to make it work slightly we have frankenstained the key fob, that why im in need of a remote to reprogram

 

[Chris]

thats a great point! But unfortunately i tried multiple brand name batteries, and now to make it work slightly we have frankenstained the key fob, that why im in need of a remote to reprogram

@Wranglerfix can reprogram them for you.

 

[Wranglerfix]

Hello guys, I need some help.! So lately my Jeep Wrangler TJ 1997 UK model has had an issue with the immobiliser key fob. It seems to work whenever it wants to and more often than not it leaves me stranded I have tried to repair the remote, but it sends a signal sometimes week or not at all. I can’t seem to find anyone that can copy the key. Is it possible to find a used one and copy it or is there any aftermarket key fob that is compatible or should I just remove immobiliser and if I do so do i just remove it or must something else be done ?

Morty-I can permanently disable the May and Skofield security in your ecm. However, it will not have any affect on your key fob.

 

[jonny jeep]

Are you parked in the same places when the fob stops working or does it happen anywhere?
There are three places, two in shopping center car parks, one on a main road where my fob won't work. Push the Jeep ten to twenty feet away and the fob works normally. Something in those areas is obviously interfering with the signal.

Long presses of the button work much more reliably than short presses for turning the immobiliser on or off.
If the the immobiliser looses sync (I think this has only happened after the Jeep battery has been disconnected for quite a while), the LED will light constantly. If it does that, I sit with the ignition on doing long presses of either button in turn, and the immobiliser always resyncs within a few minutes.

Aside from those issues I've found the immobiliser very reliable.

May and Schofield did have an option where they could add a touch key for the immobiliser but I have no idea if they could still do that and think the immobiliser had to be sent to them to add it.

Wranglerfix reprogramming to remove the M&S immobiliser the PCM is likely the best solution if you can't get the fob working.

 

[mortythejeep]

The remote is temperamental it randomly stops working and then lately got worse, never had issues with the immobiliser unit itself. Thats why im trying to get any other options other than removing it. Im in Cyprus though and not many people really work with the Jeeps

 

[mortythejeep]

Are you parked in the same places when the fob stops working or does it happen anywhere?
There are three places, two in shopping center car parks, one on a main road where my fob won't work. Push the Jeep ten to twenty feet away and the fob works normally. Something in those areas is obviously interfering with the signal.

Long presses of the button work much more reliably than short presses for turning the immobiliser on or off.
If the the immobiliser looses sync (I think this has only happened after the Jeep battery has been disconnected for quite a while), the LED will light constantly. If it does that, I sit with the ignition on doing long presses of either button in turn, and the immobiliser always resyncs within a few minutes.

Aside from those issues I've found the immobiliser very reliable.

May and Schofield did have an option where they could add a touch key for the immobiliser but I have no idea if they could still do that and think the immobiliser had to be sent to them to add it.

Wranglerfix reprogramming to remove the M&S immobiliser the PCM is likely the best solution if you can't get the fob working.

I just tried to re sync the way you described it but it doesn’t seem to make a difference. can i not copy the key fob now that it still works onto another one?

 

[jonny jeep]

It looks like new fobs are available, at least in the USA. Part number, which should match what's on the back of your fob is 56008968.

I don't know if they can be cloned using the original working fob, or if a DRBIII module would be required to program a new fob the vehicle.

I have no idea if a used fob can be reprogrammed to a new vehicle.