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S/V/C P2 R electrical gremlins - time for xemodex CEM repair?

boostdemon

creative mastermind
Joined
May 31, 2002
Location
Cary, NC
I just picked up another R, was my dads. It has a mess of issues from years of neglect. Drove it 17 hours home from Maine without major issue but here's what I've found so far:

Electrical bugs:

- no switched power coming into fuse rail for joined circuits; 12v sockets, Radio switched power, and Passenger Seat power
- High beams don't work
- Front fog lights don't work
- Alarm goes off if car is locked now after getting back to NC – Sunroof rattles, or Hard hits on suspension knocked something loose?
- No lights for active chassis settings or function to suspension settings.
- “CHASSIS SETTINGS SERVICE REQUIRED” message

Potential wiper problems reported, possible that a window was left down at some point as there was 2" of water in the drivers floor when it was picked up. No signs of leaking now. Windshield cowl had a huge chewed hole by the wiper thats been replaced.
2 Starters replaced in last few thousand miles.

Thoughts? Crush it?
 
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P2s are notorious for this. And isolating to one sole issue seems to be $$$ because one fix might not be THE fix.

I think the alarm might actually be the most simple as the dealer can do a software delete and just cancel the alarm system.

Going through it myself on an 05 VT5. Wishing you luck and following for the inspo
 
First two things I'd address. New battery and remove/replace alarm module.

Check the sunroof drains. If they get blocked, the water fills the floor.
The sunroof can be adjusted/tightened. If you're hearing it rattle, this is likely the fix.
 
Found another one... the Cruise control doesnt work. Turns on, but cant set it (or other functions)

Yeah i think i'm going to pull the CEM myself and run through it with a multimeter to check for shorts - i wish there was more information about the diagram and which circuit/relay goes to what, the list i've seen seems to be very generic or nondescript.

Battery is brand new. Sunroof drains in A and C pillars seem to be open... theres evidence of rust forming at the base of the B pillar but i suspect thats something else. Its a Maine car after all.
 
You need to get a vida dice unit.

If you get a vida unit, I'll be willing to do a video chat with you and see what we can come up with.

This can be a multitude of issues, not just one (cem). Though it could be a cem issue. Without Vida and proper diag you're just throwing money at it.

Look at the cem for corrosion.

What year R is it?

If it looks like you had water intrusion in the cab of the car, take a look at the SUM connector for corrosion or even water damage to the SUM. Could be your chassis issue.

Many issues will cause cruise not to set for safety issues. Typically though, you won't be able to engage it at all, so not being able to set it may be a sign of a bad switch.

Alarm going off can be for a bunch of reasons also. You can't disable the alarm. You can disable to mass movement sensor which is a common failure. But you need to confirm that is the failure first (with Vida you can check the last three alarm causes). Alarm siren has a battery that leaks out, also common failure. It runs on the LIN network which can cause other symptoms.

I wonder if you download the China copy of Vida if you get the proper factory wiring diagrams? They must be available online somewhere.

Jordan
 
You can't disable the alarm.

Jordan you are way more expert than me but I feel like I?ve had this done?

The bm had an alarm issue that would set off randomly all hours and kill the battery. Took it to the dealer they said they would do a software update and disable the alarm. Paid them the 120 or whatever it was and the problem was solved for a few years now.

I don?t really love my local dealership tho so I am not saying they are the last word on anything but experience seems to confirm it?s possible?
 
Jordan you are way more expert than me but I feel like I’ve had this done?

The bm had an alarm issue that would set off randomly all hours and kill the battery. Took it to the dealer they said they would do a software update and disable the alarm. Paid them the 120 or whatever it was and the problem was solved for a few years now.

I don’t really love my local dealership tho so I am not saying they are the last word on anything but experience seems to confirm it’s possible?

They probably disabled the mass movement sensor. It will solve 99.9% of issues. It is really common, of all the alarm issues I've had over the last 15 years, I've probably only dealt with 2 that weren't the MMS. We disable them all of the time.

There is no software for "remove alarm". Or "disable alarm". There is the Siren module, UEM and MMS all directly related to the alarm that would need to be removed. But, the only one with a "Remove" software is the MMS (mass movement sensor).

Edit- I have been off of the bench for a year now though. I'll try and look Tuesday to see if anything has changed, but as far as I know, none of my guys have said anything.

Jordan
 
I’m sure you’re right, most likely my mistake mixing up disable alarm with disable the alarm’s mms.

One of the things I’ve found with my janky P2 is that there doesn’t ever seem to be one simple fix for one failure.

For example mine has an airbag code and occasionally can cut the entire console display ie speedo gas gauge etc, the worst part being the signals don’t work so downtown driving around cops can be tricky trying to throw my hands out the window for signaling lol

But was told a xemodex cem won’t necessarily fix it as it could be something else causing the failure. It still drives and quite quickly so I don’t really bother worrying about it but one of these days I will most likely need to get it all sorted or give up on it.
 
I?m sure you?re right, most likely my mistake mixing up disable alarm with disable the alarm?s mms.

One of the things I?ve found with my janky P2 is that there doesn?t ever seem to be one simple fix for one failure.

For example mine has an airbag code and occasionally can cut the entire console display ie speedo gas gauge etc, the worst part being the signals don?t work so downtown driving around cops can be tricky trying to throw my hands out the window for signaling lol

But was told a xemodex cem won?t necessarily fix it as it could be something else causing the failure. It still drives and quite quickly so I don?t really bother worrying about it but one of these days I will most likely need to get it all sorted or give up on it.


So. They're right and wrong. What they're essentially saying is that diagnosis is needed. That is the problem these days. People think you should be able to plug in a computer, read a code and be able to pin point the fault. Reality is this is far from the truth. I have cars come in with 10 codes and 10 symptoms all of the time. It can all come down to one loose pin. OR, it can come down to a loose positive which has damaged a module. Or it could be a bad switch coupled with a bad wire.

Not everything comes down to a failed CEM. I see everyone in the FB R group claim it is a CEM. Every time someone has a strange problem "Must be the CEM". So these guys send in their CEM's and spend a grand having nothing fixed. Typically they have no idea how to use their VIDA, can't use a multimeter and get poor fault tracing steps from the group. Then the cars end up in the junkyard for something that is usually pretty simple. Some problems ARE hard to diagnose. CAN network faults that are not easy to replicate on a customer car for example. The faults that happen once every few months. Those are gear grinders.

Jordan
 
i had a P2 wagon. A worn out ETM can cause many other issues like no CC, no traction control. There are nice test procedures in the VIDA software to see what the ETM is (or is not) doing.
i had the same problem with the alarm system. It's usually a failed leaky battery inside the alarm unit. Not worth fixing imo
i also had some failed wiring causing all kinds of problems in the CAN network. The location was where the wires got broken/got stripped was from hinge to roof.
Cause was just fatigue and wire routing too tight.
 
Can a home gamer disable the MMS or is it a dealer-only thing that needs the subscription?

I have the bootleg Vida 2014 setup.
 
i had a P2 wagon. A worn out ETM can cause many other issues like no CC, no traction control. There are nice test procedures in the VIDA software to see what the ETM is (or is not) doing.
i had the same problem with the alarm system. It's usually a failed leaky battery inside the alarm unit. Not worth fixing imo
i also had some failed wiring causing all kinds of problems in the CAN network. The location was where the wires got broken/got stripped was from hinge to roof.
Cause was just fatigue and wire routing too tight.

Yup, throttle codes will cause all sorts of cruise issues. If you can't trust the throttle, they shut down cruise. BUT, typically you are unable to even activate the cruise when the throttle is bad, the "cruise" light won't turn on at all.
Many things cause CAM issues.

Can a home gamer disable the MMS or is it a dealer-only thing that needs the subscription?

I have the bootleg Vida 2014 setup.

So, many things changed with VIDA once the hacked version came out. Many of the functions we were able to do through VIDA without software, they then changed those functions to require software to change. With the hacked version you can still do the function changes without software. NOW, the question is, was it something you could do without software previously? From memory (7years ago), it still required software. But you could check. It would be found in the CEM if it is available. If you want to see what is setting off your alarm go to CEM, and check (I can't remember what tab they called it back in that version, maybe vehicle communications) then look for "Alarm Causes". That will tell you the most recent reasons for why the alarm went off. If it is all the same reason, you know where the fault lays.

Jordan
 
I'm working on getting a "vida" setup connected to the car... I'll let you know when i can pull some info. I have not pulled the CEM yet, but i likely will be able to check over it and fix any solder issues or broken traces. I will pull the SUM and check it as well since there was water on the floor when we got the car. (the module is by the drivers foot i'm told)

Alarm has been quiet since that first night after the 17 hour drive home... I'll check the alarm module in the fender for any physical issues
 
I remembered to check today- there is an alarm removal software - at least on the 05 s80 I looked at. That is pretty cool.

Jordan
 
Interesting information on the cruise/throttle. I've noticed that my car, the throttle has been really sensitive/jerky here lately. I've got the same symptoms with the cruise control. I can turn it on and off, but can't set it.

Damn I guess I need to break down and get a VIDA setup too.
 
Interesting information on the cruise/throttle. I've noticed that my car, the throttle has been really sensitive/jerky here lately. I've got the same symptoms with the cruise control. I can turn it on and off, but can't set it.

Damn I guess I need to break down and get a VIDA setup too.

Everyone CAN networked Volvo owning person should own VIDA. It's capabilities are infinitely better than generic code readers.

Well worth the investment.

Jordan
 
I have the generic usb dongle from ebay and I used the VM build from Swedespeed.

I tried several times to install it natively on a pc laptop but never could get it going. The VM build from swedespeed works flawlessly, but it is hard to read because the text is so small on my mac retina display.
 
You need to get the dongle like you've linked, then you need to get the vida program. The dongle my friend ordered came with the latest version of vida (2014D?). Now the problem people including him, ran into, was that the program only functioned on a certain windows/service pack. I'm sure swedespeed can walk you through it. Like Hispl mentioned.

You don't need the subscription. You would if you're going to do software, which I'm not sure you can do with the knock of dongle (dice unit) anyways.

There is a guy on Facebook/forum that sells refurbished laptops with known working dongles (some are doa/known crappy vendors) for a few hundred bucks with the proper windows etc. He has a Facebook group I believe where he sells them. Look for Dave leech. I've been really considering getting one for myself.
 
Yeah the Dave Leech laptops are pretty awesome deals.

Barring that just the do the VM (virtual machine) install like I did. It's pretty impossible to get it installed natively by yourself. Unless you are Hackerman or something.
 
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