C30 Electrics : Alarms V30

[Keith Handley]

Good day Gentlemen
My daughters C30 SD 2009 developed an electric problem a few weeks ago, diagnosed as the ECU at fault, the alarms showing and flashing are the AntiSkid, ABS and brakes. also the wipers tend to come on erratically?
I removed the ECU and sent for testing and it came back as 'no faults found'.
Today, i refitted the ECU, started the car and let it run for ten minutes, all seemed ok, then I took the revs to 2200 and suddenly everything started flashing again. I took the revs a little higher then removed my foot from pedal and for a fraction the revs still increased.
Once revs back to tickover the alarms disappeared.
Another thing I noticed is the LCD readout, for radio etc is flickering, even at tickover, increasing revs makes no difference.
My suspicion is the increased engine revs cause vibration and maybe a loose connection is causing problem.
Any ideas would be welcome?
Thank you in advance gentlemen

[lockstock]

Originally Posted by Keith Handley

Good day Gentlemen
My daughters C30 SD 2009 developed an electric problem a few weeks ago, diagnosed as the ECU at fault, the alarms showing and flashing are the AntiSkid, ABS and brakes. also the wipers tend to come on erratically?
I removed the ECU and sent for testing and it came back as 'no faults found'.
Today, i refitted the ECU, started the car and let it run for ten minutes, all seemed ok, then I took the revs to 2200 and suddenly everything started flashing again. I took the revs a little higher then removed my foot from pedal and for a fraction the revs still increased.
Once revs back to tickover the alarms disappeared.
Another thing I noticed is the LCD readout, for radio etc is flickering, even at tickover, increasing revs makes no difference.
My suspicion is the increased engine revs cause vibration and maybe a loose connection is causing problem.
Any ideas would be welcome?
Thank you in advance gentlemen

do a search on here. The CEM is prone loose or coroded connections. Also, there are issues with water damage on some cars. Basically you disonnect and clean up the CEM connectors u der glove box footwell. Follow the procedures described on here though so you don't make it worse. it requires disconnecting battery etc.


There have been instances of people causing electrical damage to the wiper circuit by fitting dodgy LED bulbs, so that may be related. If you get issues as revs rise and vibration, it could be a misfire, bad plug, injector, engine mount... bad pulley and aux belt, bad alternator... impossible to diagnose on a forum.

check CEM connections, check fuse box and wires (wheel well by front bumper), check car battery is good. check alternator is good. If all this is fine, doesnt help, you will need VOLVO to connect up for proper diagnostics. there are lots of modules and computers in these cars and you need a VIDA diagnostic to find out which one is the culprit

[MDS40]

Have to agree, sounds like the usual CEM problems.
I had very similar last year.

[Keith Handley]

Sorry for the late reply, your input is much appreciated, today is fault finding day (again)

[gmh1995]

Originally Posted by Keith Handley

Good day Gentlemen
My daughters C30 SD 2009 developed an electric problem a few weeks ago, diagnosed as the ECU at fault, the alarms showing and flashing are the AntiSkid, ABS and brakes. also the wipers tend to come on erratically?
I removed the ECU and sent for testing and it came back as 'no faults found'.
Today, i refitted the ECU, started the car and let it run for ten minutes, all seemed ok, then I took the revs to 2200 and suddenly everything started flashing again. I took the revs a little higher then removed my foot from pedal and for a fraction the revs still increased.
Once revs back to tickover the alarms disappeared.
Another thing I noticed is the LCD readout, for radio etc is flickering, even at tickover, increasing revs makes no difference.
My suspicion is the increased engine revs cause vibration and maybe a loose connection is causing problem.
Any ideas would be welcome?
Thank you in advance gentlemen

I just bought a 2009 C30, it has similar issues to this.
When the engine is running the following happens, but is much worse whilst accelerating;
- Electrics (radio / AC etc) flick on and off randomly
- Random warning lights on the dash (ABS, Anti-skid, SRS, Battery)
- "EL Current High" message

I took my CEM off and cleaned the terminals but this didn't work.

I've just (today) had my alternator replaced as it was overcharging at 17v, the mechanic said this needed replacing but wasn’t the cause of the issues and to expect the issues to return. He said it might be a relay or something short-circuiting, which is also killing my alternator. Maybe yours is something similar?