Renault Scenic 3 no engine ECU

[LD-W]

Hi all, interesting reads. I'm having bother with my 2011 Grand Scenic 1.5dci. Had a new rear, electronic hand brake caliper fitted, all was fine during a 2hrs motorway drive and back again over a weekend. Next day check parking brake warning message and spanner light came on. However, parking brake is operating as it should. Had it plugged in to 4 readers but all say there is no fault, but does say there is a communication issue between the reader and ecu. Could it be the relay mentioned or the wiring loom? Thanks for any advice, thanks