Check for water damage on pick module above rear view mirror,
unclip unit from plastic holder,disconnect and rub off any whiteish deposits from pcb, SHORTING OUT PCB
I have now placed my pcb in a clear plastic bag & sealed with sealant then, I modified  the holder so I can put the connector block on before it is refitted into the holder without puncturing the bag.
 it seems that water drips onto the pcb from antenna & or sun roofs and in some case can cause the key not to respond and unlock car and dump the codes in the ecu, I had to recode the ecu to the key as well ,change the batteries for new ones be quick as you only have about 30 seconds or synchronisation of key & ecu  can be lost !!
                
 graham_winn@hotmail.co.uk
                
 November 2008