Failing VCM?

[TheRiflesSpiral]

I'm troubleshooting an issue(s) with my wife's 2016 XC90 T6. Or, at least I'd like to be troubleshooting better than I am.

I've only sporadically been able to connect with OrBit (never with VDash) to get any information from the car. When it does connect, the connection quality ranges from Red at less than half on the little indicator bar, to Orange at about 2/3 up. I've never seen a green connection with OrBit.

Almost always, I get "VOE connection is present but the car is not responding". When I run a WireShark trace on my VOE adapter's Ethernet port, it indeed shows "50 Vehicle identification request" but no response from the car. In fact, I see a large number of packets from 169.254.158.215 (my laptop's IP) to the car but not a single one from the car to my laptop.

I don't want to pay for a VIDA subscription until I can reliably connect with either OrBit or Vdash... $100 on a failed experiment is a bit steep.

My understanding of how these units fail is that they just die. No connection at all, just a dead socket. This seems to be something different since I can, very rarely, get a (poor) connection.

A battery reset is my best chance at connecting... in all prior instances where I've been able to connect, I've previously done a complete shut down and disconnect of my laptop, then performed a battery reset (disconnect the negative battery terminal for a few minutes). A suggestion on the OrBit FAQ suggests pulling the backup battery for the VCM, to do a true power-down. I did that and left it disconnected.

That allowed me to connect once, but not since. (I have the "Volvo OnCall Service Required" message now, which makes sense.)

Anyway, before I drop $700+ on a replacement VCM, I'd like some reassurance this is actually a failing unit, not just noise in another system.

Thanks for any help you can lend!

[Bacchus258]

I just had an issue with the City Safe errors and then I could not connect using any software or scanner. I found the original 2016 VCM in a pool of water and after removing it and dumping out the water there was one pin that had rusted off. I had to buy the new VCM, new bracket that relocated it to where the existing TCM module is, the adapter wire harness, a three day VIDA subscription, and the two Volvo software updates to remove the TCM and update the new VCM. Now everything is working as it should and all scanners including Orbit connect fine.

[TheRiflesSpiral]

I just had an issue with the City Safe errors and then I could not connect using any software or scanner. I found the original 2016 VCM in a pool of water and after removing it and dumping out the water there was one pin that had rusted off. I had to buy the new VCM, new bracket that relocated it to where the existing TCM module is, the adapter wire harness, a three day VIDA subscription, and the two Volvo software updates to remove the TCM and update the new VCM. Now everything is working as it should and all scanners including Orbit connect fine.

Is this on an XC90? Maybe I'm looking at the wrong module. What I thought was the VCM is up in the passenger's side rear pillar.

[Bacchus258]

I just had an issue with the City Safe errors and then I could not connect using any software or scanner. I found the original 2016 VCM in a pool of water and after removing it and dumping out the water there was one pin that had rusted off. I had to buy the new VCM, new bracket that relocated it to where the existing TCM module is, the adapter wire harness, a three day VIDA subscription, and the two Volvo software updates to remove the TCM and update the new VCM. Now everything is working as it should and all scanners including Orbit connect fine.

Is this on an XC90? Maybe I'm looking at the wrong module. What I thought was the VCM is up in the passenger's side rear pillar.

I have a 2016 XC90 T6, and it had the original 3G VCM located in the passenger-side trunk under the fuse block and a TCM behind the passenger-side third-row side panel. The new VCM is 4G and mounts in the location of the old TCM. The first photo (Note! Orientation view) is the location of the old TCM and where the new VCM (4G model) is mounted. The other photo is where the old VCM (3G model) mounts to the right of the spare tire, under the fuse block. Maybe yours already has the 4G unit in it.

[TheRiflesSpiral]

Ah interesting! I have no idea. I'll have to do a search on the part number to see for sure. Thanks for the tip!

[TheRiflesSpiral]

Okay, I think I see what you meant. The TEM (Telematics Module) is mounted in that spot on my car. (the TCM is the transmission control module which is in the transmission housing)

So it sounds like I need to dig the VCM out from under my fuse box. I wonder if I'll find it in a pool of water? ?

Well at least I'll have an assignable cause if that's the case.

[TheRiflesSpiral]

Well, that's the problem.

I dug the VCM out from under the fuse box... it wasn't in standing water but I could tell it had been wet. That whole area is wet because the previous owner DISCONNECTED THE DRAIN HOSES. Both sides. They're just hanging there, draining into the battery well and that area under the fuse box.

So I just ordered the parts to replace the VCM. As an extra added bonus, I'll be getting the 4G modem and the relocation kit so I won't have to worry about this again.

So... I'm gonna clean my drains, re-connect them and wait patiently for the previous owner to get home so I can... uh... I mean get my Vida subscription set up.

Thanks for the tip, Bacchus.

[Bacchus258]

No problem. The new VCM comes with the backup battery so if Volvo says you need it, you don’t. Just the bracket, wiring harness adapter. Would you like a copy of the procedure with the software part numbers? One of them is a manual order and not listed in VIDA.

[TheRiflesSpiral]

Yes! That would be amazing. Also a copy of the TJ if you have it. What a lifesaver... may your family always find the missing remote forever.

[Bacchus258]

Yes! That would be amazing. Also a copy of the TJ if you have it. What a lifesaver... may your family always find the missing remote forever.

Here is the information I used to successfully replace/upgrade my 2016 XC90 T6 from 3G to 4G.