front parking sensors

[rom1]

For a few days the front park sensors started going off randomly, then I started getting red bars on front display and after that the red light for parking sensors on switch in centre console. this then disables front and rear sensors, rear cam continues to work.

Cant see any damage to sensors,
cleaned sensors in case of any dirt, but it seems there's more going on then a dirty sensor.

Looking for ideas on what it could be and possible fix.

 

[MrGreedy]

I'd imagine either a duff sensor or wiring to a sensor, possibly rubbing a wire against something compromising the insulation. I'd hope not a problem with the control module (where ever that is). Do you have iCarsoft or similar so you can scan and see if one sensor is playing up? If so, you can test the duff sensor by possibly plugging in a good sensor? But I've not had the front bumper off mine yet to see the wiring and plug arrangement. A duff sensor will be the easiest fix so I hope it's that. I bet they don't come pre painted, so either a second hand unit of the same colour or painting of a new unit needs to be considered.

 

[rom1]

I don't have access to Icarsoft or Star, I had the front bumper off about 2 months ago when I fitted the GT grille, was very careful everything went back exactly how it was, and has been fine up until 2/3 days ago.

6 sensors on front bumper, will be one of these

I think the car is still under warranty till December 2020, I bought it December 2019 and manufactures warranty finished in June, will contact local dealership tomorrow to check where I stand with this.

 

[Riva811]

I had similar issues and I am still having them. My original issue was that due to a bad battery the entire car was in limbo which caused further issues down the line. Mercedes-Benze Chelsea reprogrammed the entire car as part of an ECU updated needed and I also asked them to investigate the sensors and they said it just happens. I almost dont get it at all at the moment. No error codes were provided on any diagnostic

 

[rom1]

This ones just got strange, called Mercedes benz Leicester some absolute clown said the car is not safe to drive without parking sensors, so I went in (rarther angry) thy could not confirm if it would be covered by warranty which runs out in December, the manufactures 3 yr warranty finished 30th June the 1 yr warranty finishes in December, so I booked it in, then managed to get a date at Mercedes benz Loughbrough for next week they were much more understanding of the fault and quite straight forward about confirming the warranty.

Ironically it's now started to work properly again, the only thing I can think of is that I washed the car just before it went into this strange fault. Could be water ingress in sensor, so going to wash it again tomorrow and see if that triggers it again.

 

[Teego]

This ones just got strange, called Mercedes benz Leicester some absolute clown said the car is not safe to drive without parking sensors, so I went in (rarther angry) thy could not confirm if it would be covered by warranty which runs out in December, the manufactures 3 yr warranty finished 30th June the 1 yr warranty finishes in December, so I booked it in, then managed to get a date at Mercedes benz Loughbrough for next week they were much more understanding of the fault and quite straight forward about confirming the warranty.

Ironically it's now started to work properly again, the only thing I can think of is that I washed the car just before it went into this strange fault. Could be water ingress in sensor, so going to wash it again tomorrow and see if that triggers it again.

It's often water ingress but it still needs to be fixed, especially if you have warranty cover.

 

[rom1]

It's often water ingress but it still needs to be fixed, especially if you have warranty cover.

100% agree its very intermittent, it happens each time the car is switched off and started so they should pick something up, For some reason they seem reluctant in wanting to help, was a lot easier when under manufacturer warranty up until June, and combined with the numpty in Leicester who suggested not to drive the car and call recovery out to have a look I will be raising a complaint with Mercedes Uk once this is resolved. Hopefully by end of the week this will be sorted and I will update the thread

 

[rom1]

**Update** booked in, took them all day, said it needed a software update, now this really winds me up... it's a not a phone or a computer, the parking sensors had software designed to tell you that you are going to hit something, they still do the same job as they did on day one so why did Mercedes update the software. The response I got was sometimes the software has errors when its made so they develop updates to correct issues and take great pleasure charging you for their own mistakes.

On the plus side, it was done free under warranty and has fixed the issue.

They had the check to recommend a new number plate plinth at the grand old price of £45.... I just needed to be unscrewed and clipped back into the lower grille, which I've done.

 

[Blobsta]

If it happens again, put your ear by each sensor and you should hear a rapid feint clicking sound. The one that doesn't click is the faulty one. It's an old school trick to diagnosing them (if it's possible to have old school parking sensors)

 

[rom1]

is there a way to have the car in drive and not moving without another person holding the brake pedal?

 

[MrGreedy]

is there a way to have the car in drive and not moving without another person holding the brake pedal?

I don't think so and wouldn't risk it.

 

[MrGreedy]

For some reason they seem reluctant in wanting to help, was a lot easier when under manufacturer warranty up until June.

Call me cynical, but this sounds like either someone who is incompetent who should be sacked for failing to be able to understand even the most simple aspects of their simple job, or sharp practice to try and fob you off and give you the run around and hope your warranty runs out before you get insistent and realise you can demand to book it in. Thereby they have avoided the cost of doing any work. Either way, it says volumes about any Dealership, Merc or otherwise, who allows that to go on.

 

[MrGreedy]

**Update** booked in, took them all day, said it needed a software update

Call me double cynical, but that sounds like a ruse (porky pies) to impose an engine emissions update on you unknowingly, thereby reducing you NOx emissions by 0.01% but increasing your fuel consumption by 10%.

 

[Blobsta]

Call me double cynical, but that sounds like a ruse (porky pies) to impose an engine emissions update on you unknowingly, thereby reducing you NOx emissions by 0.01% but increasing your fuel consumption by 10%.

Well that is doubly cynical but not beyond the realms of possibility is it? I think I'd have asked a lot of questions about a software update for a PDC issue too.

Reminds me of when my Dad had a company car that kept hesitating from new it went in and out of the dealer until the adviser triumphantly explained the the issue was a faulty connection to the carburettor that had been remade. I vividly recall Dad asking the guy how it could be that a sporadic fault could be rectified by repairing the wiring to a carburettor that it didn't have? Then pressing home the issue by making them go outside and point out the carb on a 2.0 EFI Sierra. Queue vague pointing at engine and him saying"No, put your finger on the carb please. More strange than that was that he had the car for a further 2 and half years in which time it never missed a beat! Probably was just a connector not seated properly but it was fun to watch the guy squirm.

 

[rom1]

I have come to a conclusion, the issue started very soon after it turned 3 years old, whats to say the software is written to cause issues after 3 yrs manufacture warranty finishes, in my case it was still under the used car warranty, but how many more are out there with just the standard 3 years. Maybe I'm overthinking it but too much of a coincidence??

 

[rom1]

**SOLVED** After they played up again was booked in to MB Leicester, they found the number plate plinth to be at fault, replaced the plinth and fitted a new surround, was charged the diagnostic fee as the part is not covered under warranty, £164, which included the parts, now solved, not very happy as MB Loughbrough tested it after software update and said it's all working, on a positive its all working and the new plinth and surround look much better, its not the old flip top holder its the one with the removable bar on the bottom, very tidy and stealth

 

[123sean]

hi great suggestion about listening for noises as mine stopped working ,had front bumper off to no joy ,happened previously found a wet joint in boot sorted that time ..