Discovery 2 immobiliser problems

Hi. I’ve recently bought a 2005 discovery 2 and the key fob has stoped working. I have taken out the responder and dried it out on a radiator, I can normally get the car running with messing about with the battery and unlocking the car but this doesn’t always work. I was just just wondering is it worth taking out the BCU to check for water damage I’m not sure if it’s the one in the glove box or under the passenger seat or to just buy a new transponder first? Any help appreciated thanks Nick

Hi. Fit a new receiver first to be 100% ruled out as it's plug and play before you mess with the BCU cos it needs complex programming with dedicated diagnostic equipment... also if you have only one key better get a second one to rule out the fob too in such cases otherwise you might end up troubleshooting the vehicle's equipments in vain

btw... if you had to dry out the receiver i presume you have a sunroof leak so better fix that too