Vito w639 brake fluid/brake warning lights

[Dariuss]

Hi members, got annoying issue with my mb vito w639 2.2 cdi 2012 faceift model. On dash got red brake light on ( speedometer area) an brake fluid visit workshop message in messages board as on photo. These lights flashes only when raining, when climate dry, then all ok, when rain stops, lights stop flash after some time ( 1÷2h). Looks like something gets wet which trigers this problem. Brake fluid level is ok, everything works fine, no noticeable cuts in cables.... hope someone experienced such problem and can advise me where to look a problem, it would be much appreciated...

 

[BTB 500]

Hi & welcome.

There will be a fluid level sensor on the reservoir ... the connections to that are obviously exposed to water etc. when driving in wet weather, so I think that's where I'd be looking (plug/socket and wires).

 

[m80]

Above check 1st.
Common is for water ingress to the fuse / ECU / TCU / SAM enclosure.
The lid can be tricky to reseat properly.
The drainage system can cause a deluge onto the enclosure.

If it looks like there may have been ingress you really need to be sure it gets dried out thoroughly. The SAM is usually the first to suffer.

 

[Dariuss]

Hi & welcome.

There will be a fluid level sensor on the reservoir ... the connections to that are obviously exposed to water etc. when driving in wet weather, so I think that's where I'd be looking (plug/socket and wires).

Thanks for advise first. I have this issue for around 12 months, first when it happened l thought level sensor gone which built in reservoir itself, so l changed whole reservoir, firts tought problem solved ( rain gone spring come) then when had first rain problem started again ,then l realised that rain causes this problem.... which is clear now 100% as l mentioned in previous post.I have checked all cables from reservoir, abs pump conection plug, all seems ok

 

[Dariuss]

Above check 1st.
Common is for water ingress to the fuse / ECU / TCU / SAM enclosure.
The lid can be tricky to reseat properly.
The drainage system can cause a deluge onto the enclosure.

If it looks like there may have been ingress you really need to be sure it gets dried out thoroughly. The SAM is usually the first to suffer.

Thnks, its sounds where problem might be, l will have a look that area in first oportunity. Thanks

 

[m80]

If there is any doubt about the enclosure being dry I would hang a couple of porous bags of rice within as soon as.
Then be sure the lid is seated.
The 4 slide locks won't catch if it isn't, as an indicator.

The SAM really doesn't last long with any moisture around it.

Although, possibly to over heating, I have seen a distorted enclosure. One corner was lower and it would never have sealed there.

 

[BTB 500]

Common is for water ingress to the fuse / ECU / TCU / SAM enclosure.
The lid can be tricky to reseat properly.

The front lamp units are similar - I had water in one side and the dealer said it needed replacing. I declined and found the back (with rubber seal) wasn't seated properly at the bottom ... it's been fine ever since.

 

[Dariuss]

Checked fuse box ( where all electronics ecu...) all seems dry and as it should be, box lid in place..... waiting for better weather to investigate other areas.