C30 Electrics : Dreaded brake warning & electrical madness

[Droverunner]

Bought daughter an otherwise mint 2007 C30 2.0 diesel 10days ago and all was great until it had electrical madness and then wouldn't start. Fitted a new quality battery... OK for three days and now done it again. Searching on here and on Google fills me with horror about this known issue.

With ours it... showed a brake failure message, lit up ABS and anti-skid lights, wipers came on, no indicators and engine would not rev.

Can someone give me a basic description of the possible modules/ECUs involved and their locations?

[LizardOfBodom]

Originally Posted by Droverunner

Bought daughter an otherwise mint 2007 C30 2.0 diesel 10days ago and all was great until it had electrical madness and then wouldn't start. Fitted a new quality battery... OK for three days and now done it again. Searching on here and on Google fills me with horror about this known issue.

With ours it... showed a brake failure message, lit up ABS and anti-skid lights, wipers came on, no indicators and engine would not rev.

Can someone give me a basic description of the possible modules/ECUs involved and their locations?

That actually sounds like alternator issue, did you check it actually loads the battery? Its pretty common that part fail on P1 cars and when voltage drops it triggers all weird and usually false warnings.
Check alternator first, then we will dig deeper.

[Droverunner]

Hello and thanks for responding.

When we bought the car it started and ran fine but the starter span a little slowly. When servicing/checking it over I found the battery static voltage with nothing on was 12.42V which was obviously low. Idling the alternator charged at 14.7V.

We used it for a couple of days to see if the battery would come up when in regular use (car had been standing a while prior to us getting it) and it only came up to 12.5V static.

So I had it in my mind a battery would be needed soon.

Then a couple more days on it first showed the electrical madness so I thought battery needed and bought a new Yuasa 110 from Halfords. This new battery showed 12.78V static and the car started immediately with a quicker spin to the starter. Charging at idle showed 14.7V.

Now this am she has same electrical issues and a non-start... but this time it's at daughters home 90mls away so I am hoping she can get it going after leaving the battery off all day then bring it up so I can have it here a week or so.

I am experienced with electrical/electronic car fault finding but have no code reader for this car yet and no experience of the model's issues.

[SwissXC90]

Low voltage plays havoc with many systems

The car has a Low Voltage counter (2 of them) which record how often the battery is dropping too low. Check these.
And remember to reset them when fitting a new battery

You will need VIDA to view and reset the Low Voltage counters

[foneman]

I recently changed the battery on my C30 (2012) model and as the previous post says you need to reset the battery monitoring system in VIDA/DICE otherwise the car still thinks it has a faulty battery fitted.
I suggest you try and find a forum member nearby and ask for help or a independent Volvo garage with a VIDA box.You can do checks in VIDA for Alternator output etc and look at the issue in more depth,otherwise it's just guessing whats wrong.
If you were closer I would help as I have a VIDA/DICE unit,hopefully you can find someone close by.

[Clan]

Originally Posted by Droverunner

Bought daughter an otherwise mint 2007 C30 2.0 diesel 10days ago and all was great until it had electrical madness and then wouldn't start. Fitted a new quality battery... OK for three days and now done it again. Searching on here and on Google fills me with horror about this known issue.

With ours it... showed a brake failure message, lit up ABS and anti-skid lights, wipers came on, no indicators and engine would not rev.

Can someone give me a basic description of the possible modules/ECUs involved and their locations?

It seems you have bought someone elses problem ..
This fault is caused by poor connector terminals in the CEM ( main computer/fusebox ) under the glovebox , you need to get your volvo dealer to renew the network cables terminals , there are about 3 pairs of female terminals need replacing .. they should know what you mean ..

[LizardOfBodom]

Originally Posted by Clan

It seems you have bought someone elses problem ..
This fault is caused by poor connector terminals in the CEM ( main computer/fusebox ) under the glovebox , you need to get your volvo dealer to renew the network cables terminals , there are about 3 pairs of female terminals need replacing .. they should know what you mean ..

Just to add - very often you can get away with just cleaning/tightening the connectors, replacing them is last resort. CEM is worth checking anyway, regardless of your fault as it is another weak spot of our cars

[Droverunner]

>>>seems you have bought someone elses problem ..

Thanks again guys... yes seems the problem may have been passed on to us. However it came from a dealer in our village who we've bought from previously and will give a full refund when we get it back to him this weekend.

We've been lucky... had it happened 6mths on down to us.