Hello, this sounds like a intermittent break in the immobiliser wire between the ignition barrel transponder and the Nats Immu. The fault code DTC P1614 may be present with P1610, if so you will need a nats repair loom, which replaces the original wires from the ignition barrel transponder and the Nats Immu.
Part Number you require is: 24168 BN00A (around 130 for the part Nissan main dealer part only)
Should take just over 30mins to carry out the repair.
Hope that helps
Monday, March 28th, 2011 AT 9:54 PM