Any advice appreciated- spent £700 so far trying to diagnose w204 c180 electrical gremlins

[GT56]

Dear all

My C180 is causing me endless headaches

On (almost) every time the car has been started up and then driven off, as soon as it reaches approx 20 mph:
- All dash lights flash
- power steering cuts out for a few seconds
- car thinks handbrake is still on and makes assoc beeping noises for a few seconds
- doors are locked but car tries to relock them
- headlights flash on and off rapidly for a few seconds

See this youtube video- pretty much exactly what happens:

skip to 1:30 to see warning lights

the youtube video's owner says their issue was due to dodgy speed sensor but I cannot believe that 2 mercedes main dealers with diagnostic software would not be able to spot this if this was the issue.


I've taken it to my local garage and 2 mercedes main dealers- initial merc main dealer assured me that a 'software update' would fix it and charged me £400 for the privilege, before the same thing happened again straight afterwards when I picked it up and refused to refund, telling me ' the computer system told [them] it needed doing. Then charged for further time to investigate.
They then wanted to replace the start stop battery first but said it could also be the SAM and suggested that I would have to cough up £1000 for them to do the battery. I swiftly told them to **** off as I had no idea what the start stop battery would have to do with power steering cutting and the lights flashing + they already ripped me off with a BS software update.

The next merc main dealer took the car for a diagnostic check and said they needed to book it in for at least another couple more hours of diagnostics - overvoltage potentially due to bad ESP module. Interestingly no mention of the stop-start battery or front SAM ???

Both main dealers have had the car plugged into their diagnostic software with no real outcome

I'm sick and tired of wasting yet more money on a 10 year old base spec merc but won't sell it yet until this is sorted as next owner shouldn't have to deal with this BS.



Any thoughts on cause ?

I have learnt my lesson about owning an older, out of warranty merc

 

[Uncle Benz]

First thing I would do is drive the car with a diagnostic machine showing live data from the ABS module, and see what the wheel speed sensors are reading. If it happens at 20mph everytime it almost certainly has its root in those readings

 

[sausage]

Cannot offer any technical advice, but main dealers are often working to standard procedures as instructed by their computer. Non Merc specialists will likely be lost at sea with this one. Which leads me to the reason for my reply: Have you tried a well respected Mercedes independent yet ? They will not be bound by a diagnostic process determined by a computer and they will have specialist knowledge and experience.

We all say it, and it sometimes feels a bit knee jerk to say it so often, but a poor condition battery can play havoc with all sorts of electronics/electrics. I would try putting it on a recondition charge for the correct period of time and then see if that helped. If not - sorry.


Older out of warranty cars are not any great risk. I save money on the purchase price vs a new one. I've run some of the worst kind of cars to be "out of warranty" (i.e. 911 and a Range Rover) and always found it to be OK. Sometimes there are issues to deal with, but I still think it is less expensive than buying new.

NB: The 911 was under warranty for 10 years, the last 2 I had it, it was not. Thankfully the engine failed during the warranty period, otherwise I would likely agree 100% with your sentiments about older cars and warranties ;-)

Hope you get it sorted, and I hope it is as simple and cheap as a recon on the battery.

 

[brandwooddixon]

Where are you based? Someone could recommend a specialist, who will be both cheaper and more knowledgeable about older cars than a dealer.
For starters try as @sausage suggested and put the battery on a good charger.
I've seen issues with ABS, ESC and BAS flash up after reaching similar speeds due to a faulty main battery and yet go away when the battery is fully charged.

 

[AMGeed]

Take the advice of Jobsworth above, a respected Mercedes specialist.

You could do worse than contact Alex Foti, owner of AMF Automotive who can diagnose the problem.

Mercedes Servicing, Tuning, Remapping Tonbridge | AMF Automotive

Welcome to AMF Automotive Mercedes Specialists. For Mercedes Servicing, Tuning & Remapping Tonbridge come to us. We are Mercedes & AMG specialists in Kent.

www.amfmercedes.com

 

[tpn]

Just a Query/suggestion: Did anybody look at or even suggest the Can Bus?

 

[ajlsl600]

Dear all

My C180 is causing me endless headaches

On (almost) every time the car has been started up and then driven off, as soon as it reaches approx 20 mph:
- All dash lights flash
- power steering cuts out for a few seconds
- car thinks handbrake is still on and makes assoc beeping noises for a few seconds
- doors are locked but car tries to relock them
- headlights flash on and off rapidly for a few seconds

See this youtube video- pretty much exactly what happens:

skip to 1:30 to see warning lights

the youtube video's owner says their issue was due to dodgy speed sensor but I cannot believe that 2 mercedes main dealers with diagnostic software would not be able to spot this if this was the issue.


I've taken it to my local garage and 2 mercedes main dealers- initial merc main dealer assured me that a 'software update' would fix it and charged me £400 for the privilege, before the same thing happened again straight afterwards when I picked it up and refused to refund, telling me ' the computer system told [them] it needed doing. Then charged for further time to investigate.
They then wanted to replace the start stop battery first but said it could also be the SAM and suggested that I would have to cough up £1000 for them to do the battery. I swiftly told them to **** off as I had no idea what the start stop battery would have to do with power steering cutting and the lights flashing + they already ripped me off with a BS software update.

The next merc main dealer took the car for a diagnostic check and said they needed to book it in for at least another couple more hours of diagnostics - overvoltage potentially due to bad ESP module. Interestingly no mention of the stop-start battery or front SAM ???

Both main dealers have had the car plugged into their diagnostic software with no real outcome

I'm sick and tired of wasting yet more money on a 10 year old base spec merc but won't sell it yet until this is sorted as next owner shouldn't have to deal with this BS.



1Any thoughts on cause ?

I have learnt my lesson about owning an older, out of warranty merc

Is the car parked or garaged in a known rodent infested place.

 

[Wighty]

Well the op hasn’t been back so maybe that’s it ?

 

[ajlsl600]

Grand