V8/V12 Roadster Owners

[Manwhoneverwas]

For long term V8/V12 Roadster owners you might have to encounter our friend the CRM at some stage.
CRM = Convertible Roof Module
Just had mine replaced for the second time (first time was July 2014).

I asked for the old one back to see if there was any indication of reason for failure.
To my untrained eye it all looks okay, no moisture damage etc (it is housed in the rear drivers side wheel arch)

The only thing I noticed on the housing is that this one was manufactured in late 2008 and when installed in July 2014, it was 6 years old.
Current age of the CRM module at failure is now 12 years.
This one is also revision "F" and new one was Revision "H" (don't know the manufacture date of the new one).

Any electronics experts out there with advice on why they fail (vibration, moisture etc from location in wheel arch?)
Current price £498 + VAT (plus fitting etc)

[Manners79]

My understanding is that (like most electronics) they don't like getting too hot and the location, especially on a dark coloured car, can lead to overheating especially on a hot day and being not too far from exhaust heat wash. Vibration there probably doesn't help either. I had one day in the summer where my hood wouldn't operate and I'd just done a 'spiritied' drive then parked in the sun (black car). I then moved her into shade and about an hour later tried the hood again and all was fine and has been since. Could be coincidence of course.

There is another thread (either here or on another forum) about how to DIY change it. I seem to recall it is a bit of a pain and I can't remember if it needs to be coded to the car or not. You've reminded me to go and check up as it occurred to me I might see if I can source a spare to keep handy. I read up on the manual roof procedure and it scared me somewhat!

If you're in an altrusitic mood there are companies that can diagnose most causes of PCB / component failure and provide a report for a price. Just think how grateful we'd all be...! (No, I wouldn't do it either!)

[Manwhoneverwas]

Manners79 said:

If you're in an altrusitic mood there are companies that can diagnose most causes of PCB / component failure and provide a report for a price. Just think how grateful we'd all be...! (No, I wouldn't do it either!)

An update on the CRM failure, someone has asked me to send the circuit board to them and using specialist equipment they can X-Ray the board to detect "dry Joints" , "blown capacitors" etc for failure. Will be interesting to see the diagnosis.

The problem with the CRM failure is that because the module is part of the CAN BUS (network) it throws the dashboard Into meltdown.
It was amusing showing the AA guy the Xmas illuminations on the dash and even when the key was removed the dash still had warning lights on.

For any Roadster owners that the CRM module fails then there is a very easy and quick way to bypass the CRM which allows the car to be used as normal with the exception of roof operation.

Removal of Fuse 69 (5A) in the passenger footwell fuse box and also removal of Fuse 10 (30A) in the boot fusebox isolates the CRM and allows the car to be driven as per normal

[Green9]

Had exactly the same issue with my DB9 Volante. It’s a well-known problem.

Replaced it with a brand new one (date of manufacture is visible printed on the CRM) which, I’m told, is “improved”. We’ll see...!

The job took the independent specialist 30-45 mins max and yes it does need to be programmed by someone with the correct software.

[Manners79]

Green9 said:

The job took the independent specialist 30-45 mins max and yes it does need to be programmed by someone with the correct software.

Good to know that the independents can do the software aspect though, some OEMs can be a bit 'restrictive' on that frint to drive trade back to the main dealers. Now I just need to find a specilaist who can code a valet key to the car...that DOES seem to be a main dealer only capability and they just adjust the pricing upwards (a lot!) if you didn't buy the key from them.