Hello all. I have a 2004 V6 auto convert mustang. In September I left for vacation and disconnected the car battery. When I returned a couple days ago I reconnected the battery and the car started and ran fine. he keyless entry fobs would not work. I replaced a fob battery and still not working. I put it in programming mode and tried to reprogram but that didn't work either. Has anyone been through this before or is there something else I can try?

 

does the trunk release on the fob work? you could just have a power lock problem. is this 1 fob or multiple fobs? if only one 1 would lean towards a bad fob if more than 1 fob is inop i would suspect a gem module concern

 

Thank you for o=your reply. It's with both FOBs. THe fob were both bought in mid 2014 and had worked fine up until now. I disconnected the battery while I was away for 6 months. I'm thinking it could be cheap fobs. I don't know where the GEM is or if there's a fuse that controls it. The locks all work with the door switches. Also, the trunk doesn't work either. It did before. Is there any way to verify the GEM is working?

 

its tough to tell if the gem is working as its supposed to, because certain functions of the gem could fail while others stay working. you might want to take it in to get this diagnosed. the battery disconnect couldnt have caused your concern. if they arent genuine ford fobs they might just be bad, i have zero faith in cheap ebay stuff if thats what they are. to much cheap chinaese knockoff junk

 

I agree it's doubtful the GEM went bad. I think a Ford part is quitre robust. The cheap fobs did come to mind. Today I ordered 2 more fobs. I'll try that first.

 

OK...alert is over. I can be so dumb. I put the new batteries in BACKWARDS!!! So with that fixed both fobs work fine.

 

lol bet u wont do that again! happens to the best of us