About a year ago, I had a similar problem and went to the dealer who explained how to reprogram the security system in case the car "forgets" the pendant code. It fixed the problem that time. The process was to cycle the ignition 5 times (from off to on) within 5 seconds and immediately aftwerwards press any button on the remote. A Volvo can remember any pendant code this way. I had also had the problem of contamination preventing the pendant from transmitting properly. Coke or coffee or something got in it. I dissasembled it and cleaned it with a toothbrush and aclhohol. After drying and new bats it worked again.