I have had this peculiar problem since buying my Renault Master, 3 years ago.
The immobilizer usually works fine however if I park the van in the hot sun, when I try to start it, I get the immobilizer light flashing rapidly.
I have 2 keys and the same thing happens with both.
I have opened the immobilizer ring and cleaned the circuit with a brush but did not make any difference.
As a temporary solution, I have kept the ring outside the case and I move it closer to the top of the key (where the chip is), every time I get this issue.
Anyone experiencing the same thing?
What is the cheapest way to solve this issue? If I was to get another immobilizer ring case and swap my circuit for the one in it, would it make any difference?