ABS & ESP fault showing on Dash, but NO CODES.

[PDeeley]

I have a Merc W221 S 320 Diesel 2007. It has suddenly developed a fault on screen that ABS & ESP fault. This will remain for hours/days/week and disappear only to return again. My local garage that has Merc & BMW trained mechanics can find no fault codes on the cars system and has checked the sensors and found continuity whatever that means.
It does not seem to affect the car or brakes as far as I can tell, but is aggravating to say the least. Any ideas as to what the mechanics should look at as they are totally confused by it.

Many thanks for any help given.

Peter

 

[mioba]

ABS control module I would say. Had similar on my W220 a few years ago. Not cheap and need marrying to the car.

 

[PDeeley]

ABS control module I would say. Had similar on my W220 a few years ago. Not cheap and need marrying to the car.

Many thanks. Did your problem give a fault code at all as mine doesn't for some reason?

 

[Wighty]

What about brake stop switch , it’s cheap £15 ? Also it’s a consumable part ?

 

[Taffy7hfa]

I experienced a similar issue when the battery was in the early stages of dying, after eventually fitting a new battery the random ABS/BAS/ESP lights stopped.
Low voltage/voltage drop (often on on start up) can cause all sorts of weird and puzzling things to happen on these cars....too many pesky computers !

 

[mioba]

Many thanks. Did your problem give a fault code at all as mine doesn't for some reason?

No fault codes. Only the error on the dash.

 

[brandwooddixon]

You can quickly and cheaply check for a low battery voltage issue by connecting another good battery in parallel, as if you were jump starting the car, before you attempt to start the engine.
This will mitigate the voltage drop under cranking that may trigger ESP/ABS lights triggering on start-up.

 

[Botus]

no errors (I doubt),
I expect they get no communication with the module
all ABS modules are easily repaired for not much money
so long at its not got SBC then the basic hydraulic braking should still operate - but the pressures reaching individual wheels may not correct (stand on the brakes and see if it skids?)

if any wheel does the ABS isn't working - which is the point of the light on the dash - FYI if you crash with the error and it goes horribly wrong = death by dangerous driving

had on one car and one bike where individual wheels lock with low braking effort in random fashion - not safe

 

[mioba]

Nothing like filling a man withconfidence Botus