What did you do to your Volvo today? Topic is solved

[454cid]

Clutch job….

That is something I'd definitely rather not have to do. The amount of heavy auto work you do in the driveway is amazing.

[xanthefin]

I am suddenly happy feeling as i was today looking what is CEM box on 99 / 00 years V70's.. i couldn't find from schematics and such saying...

Finally the dataline schematic got my attention about the dashboard.. the stupid dashboard (COMBI old term, CDM term for 99, 00 years) is the CEM box which holds all VIN code etc..


I had one laying around almost used for parts as got for free from friend long time ago.. now got good usage for it!


Learn more every day.

[scot850]

Just so you know, the circuit board in the CEM cannot be re-programmed. It is a one-shot program unit which has the VIN#, mileage, but also through which VIDA accesses the ECU and TCU. It also stores the transmission type in there so you can't use a 4=speed auto on a 5- speed auto transmission for example.

Neil.

[xanthefin]

Just so you know, the circuit board in the CEM cannot be re-programmed. It is a one-shot program unit which has the VIN#, mileage, but also through which VIDA accesses the ECU and TCU. It also stores the transmission type in there so you can't use a 4=speed auto on a 5- speed auto transmission for example.

Neil.

Hmm talking about dashboard here? I have here 1999 Dash (CDM) which holds all this information and i see flash memory on board but I am not yet interested programming this. I have had enough fun with IMMO3 encryption and programming it when it gets corrupted. In schematics i don't see CEM on this year model at all and CAN Bus goes through this dashboard which has CAN Bus relay on board which clicks when commanded to open CAN Bus (Like on 2001 years CEM does same) which has ECM, ABS, TCM (this has Kline too!) behind it in schematics.

Rest of system is on Kline like old systems and goes directly old fashioned way to OBDII port as is. Dashboard doesn't control their opening. But i understand Kline protocol may have slightly changed between 1998 and 1999 but hasn't stop my ELM327 reading them though.

If talking about 2001 and newer yes.. CEM is gate keeper.



1999 schema, no CEM. Dahsboard is CAN Bus gate keeper. Rest system in K line.

[scot850]

Interesting indeed. When I was having CEM issues with my 2000 R last year, I tried fitting a CEM from a 99 (with 4 speed auto). My Vida system would not let me access the ECU and TCU as they did not match.

Neil.

[bmdubya1198]

The ECM and TCM communicate via the CDM (cluster), so if it's not correct, you'll have communication errors. As far as I know, the '98 and older cars do not have any communication to or from the ECM to the cluster. Well, not CAN bus at least. Of course there's a need for the tach, temp signal, etc.

[xanthefin]

Interesting indeed. When I was having CEM issues with my 2000 R last year, I tried fitting a CEM from a 99 (with 4 speed auto). My Vida system would not let me access the ECU and TCU as they did not match.

Neil.

I have heard earlier about early CEM being different and so please if you don't mind leaving (if not here then pm) p/n of this CEM box and VIN code of your R. I'd love to know more detailed what is what.

Thank you!

[bmdubya1198]

I believe the CDM would be what you're looking for, there is no CEM on P80s.

[abscate]

Clutch job….

That is something I'd definitely rather not have to do. The amount of heavy auto work you do in the driveway is amazing.

I’m not in the same league as many others here , like bdub, foggy, and My favourite Scot

[scot850]

You definitely are in that league and in some ways ahead of us. So don't sell yourself short! There are many hear who have benefited from your experience and knowledge, in my case on that dam electricery stuff!!

Neil.