What have i missed? Bromsfel Stanna Omgående

[Giveitgass]

Hi all! I have a 1999 Volvo S80 2,0t (b5204t4) I feel like i have tried everything possible, yet it's still having issues.

The symptoms have been a little different over time as I made some repairs and attempted fixes, but the main issue still persists.

Every now and then, the dreaded "Bromsfel Stanna Omgående" pops up in the dash. Along with this the speedo, RPM, temp, trip and clock gagues in the dash go blank. in this state, the car will not start (but it will crank), but will continue to run if the engine is already in motion. It does however judder quite heavily while going from gas on->off, and all throttle inputs will be ignored when braking.

So, let me give some details.
With the engine not running (most of the time):
when turning the key to pos 1 and 2 everything is seemingly fine. Then when trying to start the engine the RPM needle usually goes up a little bit with the starter, but every now and then it won't. Thats how you know the fail is there. The engine will briefly start but after a quick second it shuts down and the message comes up in the dash.

with the engine running:
Everything goes seemingly fine, but suddenly the Speedo dies, shortly followed by the rest of the dash (except for ODO and Fuel gague). then the message pops up in the dash and symptoms are as stated previously. It has a rough idle at this point and won't start back up if shut down.

The only way to get the car back up and running is to go in the back and disconnect the battery for a little while, which is really annoying. Just waiting it out or clearing codes will not work.

Another possibly related issue is that sometimes the Cruise will cut out. you press the Cruise button and Cruise is activated in the dash. then you try to start cruising by pressing the + or - button, but when you do the Cruise word disappears from the dash and won't turn back on. This can happen the first time you try to cruise during a trip, or while you have already used cruise a few times.

Another detail is that this happened a lot less during summer, but don't know how relevant that is.

I got to extract codes from both VIDA and VDASH2 very recently when the fault was prevalent. Here are the relevant codes:

- CEM-E000
- CEM-1A5D
- CEM-1A55
- ECM-928C
- ECM-0023
- ECM-720A
- ECM-E003
- ECM-912A
- BCM/ABS-0095

So far, here are the things that have been done to the car:
BCM replaced
ETM replaced and reloaded
Engine bay grounds replaced
All relevant connectors cleaned and checked for corrosion
Checked water drainage
Replaced left front wheel speed (ABS) sensor along with reluctor ring
Cleaned right front wheel speed (ABS) sensor
Tested ABS pump function via VDASH2
Tested DIM function via VDASH2
Checked connector box left of battery
Checked relevant fuses
Tested canbus from BCM, ECM, ETM and CEM with ohm meter
Tested ABS function on slippery surface
Tested charging voltage with car running


Would love some insight, i feel very lost at this... Possible canbus junction point failure? the whole CEM needs replacing? Any input is greatly appreciated:)

[scot850]

Where is the CEM situated on a S80? You appear to have a lot of CEM codes but no mention of anything been done about it.

Neil.

[Giveitgass]

Where is the CEM situated on a S80? You appear to have a lot of CEM codes but no mention of anything been done about it.

Neil.

The CEM is located under the dash behind the OBD port. I did take it out and spray down the connector with contact cleaner, but otherwise not much else. I have been dreading needing to replace it, so I did everything else I could in hopes I wouldn't need to Could possibly try to replace all the relays on it?

[scot850]

Looking at the CEM codes they are all communication code errors. First one is General CEM comm error, 2nd is CEM to ETM comm error, and last one is CEM to DIM comm error.

This makes me wonder if it is an ignition key and immobilizer issue. If the antenna is going bad, the immobilizer chip is going bad in the key, or the electrical part of the ignition switch has failing contacts, all could cause intermittent issues which make the car systems fall over throwing codes.

Another issue that these cars don't like are weak batteries. If you have a bad cell, or weak alternator output it could cause random errors.

Does your car have the Magna Marelli ETM? When you say you have replaced and reloaded the software, did you do that? Is the ETM new or a rebuilt unit?

Neil.

[Giveitgass]

Hello! Could be immobilizer, i have not done much to that part of the system. Will try to clean up the antenna connector and drive with spare key for a while. Battery was replaced and alternator output was checked, but i can check again for controll.

The ETM is (unfortunately) a Magneti Marelli unit, got a refurbished one. Was reloaded by a Volvo mechanic. everything went fine during this process and all issues i had with the ETM dissapeared.

Thanks!

[scot850]

When you clean the antenna, look inside it as they crack with age so they then do not work. Not too terrible price from Volvo last time I bought one new.

Neil.

[Giveitgass]

When you clean the antenna, look inside it as they crack with age so they then do not work. Not too terrible price from Volvo last time I bought one new.

Neil.

Have now used the spare key for a bit, which didn't work so i replaced the entire immobilizer antenna unit but the issues still persist. Canbus junction points perhaps?

[scot850]

It may be your DIM is failing. The only other issue as the symptoms like speedo dropping out could be the DIM is failing with age and temperature which is not uncommon at this age. The speedo can also drop out because of ABS issues, but then I'd expect the ABS light to come on.

Apologies, but my Norwegian is extremely poor. The warning message you get, do you know what that might be in English?

It is unlikely, but it is possible the chips in the keys are failing or failed. We had that happen on one of our keys. I bought ships off Ali Express and fitted them into the keys. I had to buy a third key and get them all programmed as the dealer could only do it with a barcode off the packaging. Hopefully it is not that.

Last thing might be the electrical contacts in the ignition are worn.

Neil.

[volvolugnut]

It may be your DIM is failing. The only other issue as the symptoms like speedo dropping out could be the DIM is failing with age and temperature which is not uncommon at this age. The speedo can also drop out because of ABS issues, but then I'd expect the ABS light to come on.

Apologies, but my Norwegian is extremely poor. The warning message you get, do you know what that might be in English?

It is unlikely, but it is possible the ships in the keys are failing or failed. We had that happen on one of our keys. I bought ships off Ali Express and fitted them into the keys. I had to buy a third key and get them all programmed as the dealer could only do it with a barcode off the packaging. Hopefully it is not that.

Last thing might be the electrical contacts in the ignition are worn.

Neil.

Chips not ships?
volvolugnut

[scot850]

Trouble of being Dyslexic and fat fingers!!

Neil.