V50 battery disconnection

[Ashmere]

55 (06) v50 2.0d

I need to disconnect the battery for some time poss a few weeks whilst I get some modules tested, will this cause any probs?

[IainG]

Hi
I have heard that with this engine the ECM can loose its memory/program if left powered down for a long period. Others might confirm or not?


Iain

[Clan]

Originally Posted by IainG

Hi
I have heard that with this engine the ECM can loose its memory/program if left powered down for a long period. Others might confirm or not?


Iain

yes this I have come across a handful of times on the early cars , It will need to be towed to the dealer for an ECU reload if that happens . Only 2.0D ECUs however.

[Simmy]

Originally Posted by Clan

yes this I have come across a handful of times on the early cars , It will need to be towed to the dealer for an ECU reload if that happens . Only 2.0D ECUs however.

hi clan dose this apply to 2.0d c70s aswell ours is a 2010

[Clan]

Originally Posted by Simmy

hi clan dose this apply to 2.0d c70s aswell ours is a 2010

yes it does !

[Ashmere]

So what is the time limit with no battery connected before meltdown and access denial?

[Clan]

Originally Posted by Ashmere

So what is the time limit with no battery connected before meltdown and access denial?

This is a rare problem but if it were going to happen a few days without power could cause it.

[Ashmere]

I expect it will be a week or so whilst I send the Ecm and brake module for testing so likely it'll lock out then.
Again another stumbling block which means dealer only reset. Seems there's no way out of it whichever route I take.

[Clan]

Originally Posted by Ashmere

I expect it will be a week or so whilst I send the Ecm and brake module for testing so likely it'll lock out then.
Again another stumbling block which means dealer only reset. Seems there's no way out of it whichever route I take.

not likely at all , just a very small chance it will .

[pinballdave]

I don't think anyone really knows what causes it, it could be disconnecting the battery while the ECU is still active, it could be a failure due to low battery voltage, it could be a spike while reconnecting the battery.

All we know is that these kinds of events happen all the time, I expect most of us have suffered from battery problems and/or disconnected and reconnected the battery many times, for long or short periods, and our ECUs are still fine. It's very rare but one day it could happen to any of us (at least those of us with 2.0D engines, the rest of you can just worry about the airbag CFFF error!).

The good news is that if it does happen, there's a few ways to fix it. Either take the car to Volvo for an ECU reload, or there are many third party specialists that can read the CEM data, the ABS module serial number and re-sync the immobiliser code in the ECU. (I even have the tools to do this myself!).


You seem to have a lot of threads about your issue, some talking about CEMs, others about ECUs and batteries, each with a different isolated question, and some of the answers given (including my own) are appropriate for the question asked in the particular thread, but given the whole picture a different course of action may be more appropriate.

I'd suggest choosing one thread, and updating it with all the details of the problems you've had, the things you've tried so far, and then keep all new questions and comments in that one thread.


From your thread with all the fault codes, a lot of them appear to be related to can bus communications. This is a common problem on these car models. The suggestion of checking the CEM for corrosion and cleaning the contacts of it's connectors, can be a quick fix for this problem, but it's more likely to be due to a few connector contacts in the wiring to the CEM that were poorly specified by Ford and are a weak point, if these are not replaced, then the fault can re-occur.

Sometimes it can be caused by a worn out battery, or a failing alternator causing electrical noise on the communications bus.

But it's very rare for it to be one of the electronics modules themselves. So removing them and sending them out for testing, before checking and addressing the common causes is unlikely to be productive.