complete immobilisation driving me mad..

Hi, there are some posts on here about immobilisation but mine is not covered - grateful for any help. I bought a C3 2016 1.0 PureTech and from day 1 of getting it home ( private purchase ) there's an issue with it going into full shutdown/immobilisation/no power when I turn the ignition key. It's getting progressively more frequent and the only solution is to pop the bonnet, jiggle the battery in its compartment or give the battery plastic cover (under which all the connections are) are whack. Then the power is all restored and it will start. All connections are tight and rust-free. The shunt fuse is ok, I've done the long-winded reset advised elsewhere. The only other time an action cleared it was when I slammed the rear passenger door in temper when it was immobilised and all the power came back. Cheers.

Hi

I would start with the battery.

A battery with faulty internals can give trouble, obviously it is intermittent and the battery may test ok, but that's how intermittent goes

Very much obliged, Sir. Love this forum