Help! Bricked CEM, possibly other modules Topic is solved

leapdragon · Post by **leapdragon** » 02 Apr 2025, 12:49

So against my better judgment, I decided to use the rest of my VIDA subscription to run a "Total Upgrade CAN" (upgrade all modules) for my 2002 V70XC. I completed the TCM upgrade yesterday with no problems and it actually fixed my transmission.

However, the Total Upgrade CAN failed and the CEM is now offline. Car does not start, turning ignition to key pos II does nothing but illuminate "check engine", and I can only connect to the vehicle in VIDA if I enter the VIN manually. After entering VIN manually, I am able to try to program again, but I've been through this about 20 times and it always fails.

DICE unit tests as OK
External power source is attached to vehicle
I have tried disconnecting power (all sources) for 15 minutes, but I just get the same thing when power is re-applied

How do I un-brick this car? Anyone been through this recently?

I found Volvo https://www.tsbsearch.com/Volvo/TJ-27236 that claims to document how to program modules that have gone offline, but none of the controls correspond to anything that I can see in VIDA (i.e. I do not have any "SEND PROG" or "RESET" or anything like that). There are some threads online where people talk about doing things in the "Software->Advanced" tab, but the Software section appears not to have an advanced tab any longer.

Does anyone have any advice / have strategies to get this back online? I am unlikely to pay they $thousands the dealer will want to do the reprogram.

dikidera · Post by **dikidera** » 02 Apr 2025, 14:17

Talk about damn luck. Is it possible to do it on a module per module basis. Also which modules are not live?

@vtl you jinxed it.

leapdragon · Post by **leapdragon** » 02 Apr 2025, 15:31

So... some updates.

Right now in VIDA it can't read the VIN, DIM is dead, car appears dead except steady "check engine" light. However, if I try to read VIN in VIDA, it will ultimately say it can't read VIN and then prompt for VIN. After prompting and entering, I can get a vehicle readout.

CEM, SAS, PHM, AEM, and RTI are all offline (red)

I did find the button referenced in the recovery doc (it appears to have moved/changed a bit) and can get most modules to go into programming mode (including CEM), though SAS PHM, AEM, and RTI won't (perhaps these depend on CEM?)

However, from programming mode I can neither flash CEM upgrade nor Total CAN Upgrade, it errors out immediately, doesn't even start. The error message is generic—check voltage, ensure that cables are plugged in, etc.

Voltage with a multimeter is ~13v and I generally know the setup works as I just reflashed TCM the other day.

Any ideas? Do I need the reload P/N rather than an upgrade P/N? And any suggestions on how to go about finding a reload P/N for CEM?

leapdragon · Post by **leapdragon** » 02 Apr 2025, 16:23

More info:

Have also tried CEM reload PN 9438273

All fail in the same way--first status message "Checking wake up patterns" appears, cabin fan stops (it is running 100% of the time when power is applied / battery is connected right now), and then it says "Download failed" and provides instructions to check voltage, make sure the device is plugged into the car and the computer, etc.

I don't think this is about the particular module. By going into "Advanced Test" and enable programming mode, I can get the HW# and PN# as mentioned in https://www.tsbsearch.com/Volvo/TJ-27236 which seems to suggest I ought to be able to flash.

But it fails right at the front end at "Checking wake up patterns".

I know this setup can be used to flash as I've done keys and fobs on both cars as well as the TCM update just a day or two ago.

Anyone seen this before?

Post by **vtl** » 02 Apr 2025, 19:37

Did you power your DiCE with external power source? Also is it a good DiCE?

Post by **vtl** » 02 Apr 2025, 19:42

leapdragon wrote: ↑02 Apr 2025, 15:31 I did find the button referenced in the recovery doc (it appears to have moved/changed a bit) and can get most modules to go into programming mode (including CEM), though SAS PHM, AEM, and RTI won't (perhaps these depend on CEM?)

Yes, CEM controls power for those modules, I think. Need to recover CEM first.

Did you follow the procedure in pdf you mentioned? Like power DiCE externally, disconnecting battery, etc?

Post by **vtl** » 02 Apr 2025, 19:52

Do you solder? The last resort is BDM programming via Arduino solderi a few wires to CEM. See viewtopic.php?p=660491#p660491 and viewtopic.php?p=609357#p609357 and generally search for BDM in that topic.

leapdragon · Post by **leapdragon** » 02 Apr 2025, 19:59

Hi guys,

Yes, DiCE is externally powered by a 12v adapter w/10 amps available. Have tried both procedures in that Volvo rescue doc. I think it's possible that the problem is that we're not staying in programming mode—when I enable programming mode, VIDA confirms were there and I can get the HW# and so on no problem. Entering programming mode causes the fan to die off and the lights to go out.

Problem is, the doc thinks you can exit the Advanced Test mode and (it clearly says) the module will stay in programming mode. However, when I close the Advanced Test window, I can hear relays engage and the lights come back on and the fan starts again. This makes me think that we're not staying in programming mode for some reason.

Part of me is toying with the idea of trying to get VIDA 2014D live to Volvo's servers (i.e. the real version), as in the past I've always used the older version. The current install worked for the TCM update the other day, but it's a new installation of the most recent version because the laptop where I had 2014D live to Volvo died.

@vtl In a former life (I'm getting old) I was a pretty decent hardware and software hacker. Arduino is after my time, but there's no reason I couldn't figure it out, and I do have soldering equipment. I even have multiple brand new Arduino units sitting around in the house here that I intended to play with and haven't started yet.

But that said, the thing I keep seeing in all of the posts about CEM out and reflash is needing a dump of a CEM.

Can you provide any details on that? Where would I get a CEM dump to use to reflash with?

Post by **vtl** » 02 Apr 2025, 20:21

Ask in that topic for help, someone will PM you. I'll look around if I have any dumps tomorrow.

Post by **vtl** » 02 Apr 2025, 20:23

Also try to put into programming mode, pull the DiCE from OBD, close the tab/window, wait a few seconds, connect DiCE back.