Remote fob stopped working

[andyda8]

Hi all.
I have a 2004 Cherokee (Liberty) KJ 2.8CRD Limited. Remote suddenly stopped working. Changed battery, case, cleaned circuit board contacts etc. Tested with a radio frequency tester and found it transmitting 433Mhz. Also bought used remote online and tested this too.
Central locking works via the driver door switch so all doors are ok.
Tried reprogramming my original remote plus the used one using a scanner. Scanner screen tells me programming was successful and I heard the chime after programming each remote BUT the remote lock/unlock still doesn’t work even though the remotes appear to have been programmed successfully.
While playing around with my scanner checking for fault codes etc I did see a code (P1685 - SKIM symptom) at one point and also a couple of messages saying ‘NO BUS MESSAGES RECEIVED FROM BCM’ and ‘BCM MESSAGES NOT RECEIVED’.
Ignition key is non-remote transponder and I have no issues with that.
I’m thinking a maybe a faulty BCM (or plug in RKE) module, wiring/connection fault (but wouldn’t this also cause other issues?) or possibly low car battery voltage as I only use it weekends, but I did recently charge it overnight.
Any help or ideas would be much appreciated.

 

[Ksat]

Just a shot in the dark, but you may want to check all fuses in the vehicle and, if those check out, check for power and ground going to the BCM. Earlier Liberties apparently had the RKE (Remote Key Entry) module plugged onto the outside of the BCM whilst later KJs have it integrated into one unit. Not to confuse you, but I've also heard, instead of being on or integrated into the BCM, that the RKE is part of the SKIM module (combined SKREEM), which is in the column where you insert the key.

You may want to take a look at the shop manual to help clear that up. You also may want to try disconnecting the battery cables, touch them together then reconnect to see if anything changes.

 

[Deb'nKJ]

Best advice I can offer is, these things have a finite life, then you go back to using the key.