Hi folks, need help to troubleshoot CANBUS communication issue on a 08 XC90 3.2:
Got ABS/Anti-skid service required message, and corresponding warning lights are on. After the vehicle restart, the message and warning lights disappear within one minute and then come back in a few minutes. AWD and ABS not working but otherwise drives fine.
Tried to scan in VIDA and found BCM, DEM and ECM offline (Red) and TCM is gray.

First thought was DEM as the fuse burnt twice during the winter so removed it from the network by unplugging the socket.
VIDA network still the same as above, now with CEM-1A64 code. Re-connect the DEM then the CEM-1A64 was gone. No other code pop up.
Checked resistance at the OBDII socket between CAN high and low, it's 61 ohm. Ground line 1.2 ohm to chassis ground terminal. No short-circuit to supply voltage nor open-circuit detected. Visually checked the cables and sockets on DEM, REM and ECM, seem to be fine. Also checked fuse 15 on CEM to confirm it got the power (~14V).
Got stuck here and need help with further troubleshooting. A

ppreciated!

 

Grey is offline/no communication or not in your car, green is no codes in that module, red is codes stored in that module - can you post a printout of all modules and codes? You can print a one page list

I trust you don't have turning headlamps (hcm) satellite radio (rdar), a sub woofer (sub), or GPS - so they (and many others) are all grey. You do have a transmission! - (tcm) so that module should respond.

 

Thank you hoonk for the reply.
This is the strange part. The delivery tab says no fault found however you can see those modules were grey out.


If I disconnect the DEM, then I get the CEM-1A64.


CEM-1A64 disappears when I reconnect the DEM.
My guess is that CEM can't talk with DEM,BCM, ECM and TCM so won't be able to retrieve codes from them? But in that case, I should see some code related to communication issues?
Also, if the TCM is really offline, I guess the car won't be driveable? But it drives okay.
This really puzzles me.

 

In 2018 I purchased a clone DICE - it would not talk to all the grayed out modules (at least the ones that were in the car CCM, DDM, PDM, RDAR etc.). Vendor sent a replacement and it worked. Are you using a clone DICE?

 

Thank you hoonk!
Yes I am using a clone DiCE purchased a few years ago. It talks to BCM and ECM before as last year I got BCM-U042864 Invalid data received from the steering angle sensor module (SAS), Replaced the steering angle sensor and resolved the issue. Also had ECM-P045500 Evaporative Emission System Leak Detected before and turned out to be a crack in the fuel intake line. At least DiCE was communicating with these modules then. Any chance the DiCE fail after last use?