Pretty much as the title suggests, I've been experiencing worsening problems with the head unit in my E55 with it not springing to life when I start the car, sometimes taking anywhere from five minutes, to an hour, to not at all before it powers on.

Once it's on, it's fine for the rest of the journey.

I did have two other electrical issues which I've now resolved:

Passenger occupancy sensor fault causing SRS error. Replaced, fixed.
Battery dying after more than a few days disuse. Found the battery to have a high self-discharge. Replaced, fixed.

Comand 2.0 still doesn't want to play ball though.

I've been out to the car today to test fuses, voltages and wiring.

All fuses beep out OK on my meter.
New battery showing 12.7v with ignition off, 12.4V with ignition in Positoin 2, and 13.95V / 14.05V with engine running.
Removed ashtray / CD-Changer / Head Unit, all seemed to be connected securly but I've removed and reconnected everything just in case.
Still no life from the Comand.

I think I aught to replace the Comand. It's P.N A2118272442 which seems readily available on eBay for a good price.

Anyone disagree? I'd value anyone else's opinion before I waste any money chasing the wrong part.

Also - are the Comands a drop-in replacement or will things need re-coding? Is it a "Battery disconnected" job?

Thanks muchly for any advice

 

Replaced Comand with another identical part number from eBay and it's working flawlessly, no need to recode. Happy days