Can-bus guru's advice needed please. Topic is solved

[precopster]

Do some probing as per jimmy57s post on 5th March. You will probably find that BCM is the corrupted module.

You can even remove BCM and test the car over short journeys. Yes there will be multiple flashing lights but you will still have hydraulic power assisted 4 wheel discs which is a lot safer than many small cars without this.

[Free2drive!]

Bit of an update!

Car failed its inspection. One seized front caliper and the other one leaking.

I've replaced both front calipers and brake hoses, discs and pads. No more anti skid/brake stop safely messages.

All I get now is a drop into limp mode then transmission service after I restart. The speedo drops and CCM drops out everything else works.

This has happened twice in the last month.

Car shifts fine and just throws up no communication with ECM, TCM and CEM.

Any ideas?
Thanks
Matt

[precopster]

If it's a speed sensor fault that relates back directly to the BCM.

Car needs to be read with Vida

[mrbrian200]

Is there a common connector point for the CEM, TCM, BCM and ECM?

If you're talking about power distribution, ground points are varied but studying the diagrams there is a +B that is shared between these all 4 of these modules, originating from one or both of the larger red +B wires running into the CEM direct from the trunk: Powers the CEM and appears to branch out internally through fuses located on the CEM that supply +B to one or more circuits in the other 3. The ECU gets +B from several parallel circuits, one of them comes from the CEM. It's difficult to say whether this is always on or switched with an internal relay just from looking at the diagram.

[RazieL]

Bit of an update!

Car failed its inspection. One seized front caliper and the other one leaking.

I've replaced both front calipers and brake hoses, discs and pads. No more anti skid/brake stop safely messages.

All I get now is a drop into limp mode then transmission service after I restart. The speedo drops and CCM drops out everything else works.

This has happened twice in the last month.

Car shifts fine and just throws up no communication with ECM, TCM and CEM.

Any ideas?
Thanks
Matt

Hello, i'm currently having the same issue with my 2013 v40. As i was looking through the internet i stumbled upon this post. Did you ever resolve it? What did it turn out to be?

I realize this is a quite old post but i'm trying my luck this way. Car's been in the shop in and out since December 2019...

[AKellner]

Did this ever get solved? I am having the EXACT same issue on a 2011 Volvo C30 R design geartronic.

[RazieL]

Not for me. My car is currently fine, but this is most likely just temporary as we have yet to find an actual "problem"

[AKellner]

Well, you said you have the same issue, i'm curious to see if we have the EXACT same issue. If that is the case, we can start checking for other similarities between our cars. I mean, the same problem will have the same cause, right?

[AKellner]

Mine started out as a transient issue, as well. Now, the car can't even be called drivable. I'm still waiting on a dice scanner but these are the modules reporting errors in the onboard diagnostics.

[RazieL]

In your case, looks like its a different generation than mine. I also have a 2005 v50 - display looks exactly like yours. These ones are notorious for oxidation issues in the ECM/ECU -whatever the unit in the passenger foot-well is called. Just pull back the carpets, unplug everything (carefully and after disconnecting the battery) and use some electrical contacts cleaner, depending on your location you should find some pressurized/canned air and maybe even open up the unit and use some cleaning spray for electronics.

not sure what the politics on this forum are regarding YT videos, but this is what i mean: