Ml 350 Software recall and knock sensors

[paul243]

Thought this may help ML350 owners..
Just had a software recall today to be advised that 2 knock sensors need replacement. Seems a full diagnostic is done with the update.
Was about to empty the bank when the service manager explained that they would be replaced FOC! ,car collected and returned.
Seems that there would be a good chance of free replacement irrespective of the recall.
Suggest if you have similar problems try for a "goodwill" replacement.
Car is a 2014 with 36k and full Merc.history
Hope this helps!

 

[ernie]

Thought this may help ML350 owners..
Just had a software recall today to be advised that 2 knock sensors need replacement. Seems a full diagnostic is done with the update.
Was about to empty the bank when the service manager explained that they would be replaced FOC! ,car collected and returned.
Seems that there would be a good chance of free replacement irrespective of the recall.
Suggest if you have similar problems try for a "goodwill" replacement.
Car is a 2014 with 36k and full Merc.history
Hope this helps!

Think you mean the NOx sensors which control the injection of AdBlue which reduces the pollution from the oxides of nitrogen. They are troublesome and have been updated several times, but still they fail. If you had to pay for their replacement yourself, you would be looking at £1200 or thereabouts.

Ernie

 

[paul243]

I thought he said "knock" but will check. Quoted "over £1000" if I was paying. Would Knock sensors be that cost?
Strange that my indie didn't spot the codes when he replaced a turbo temp. sensor recently!?

 

[Deleted member 65149]

I thought he said "knock" but will check. Quoted "over £1000" if I was paying. Would Knock sensors be that cost?
Strange that my indie didn't spot the codes when he replaced a turbo temp. sensor recently!?

Knock sensors typically cost £50 - £100 and are easy (therefore cheap) to replace. I’d be certain that it’s the NOx sensors that need replacing. I recently had them replaced on my C350 without having to pay the £1200 charge because they’re a common fault.

 

[paul243]

Is it possible that the software update produced the fault codes or were they already defective? I had no engine light on.
Maybe I've just been lucky?

 

[ernie]

Is it possible that the software update produced the fault codes or were they already defective? I had no engine light on.
Maybe I've just been lucky?

I've just had to have one of mine replaced under warranty. The car was serviced in January and the Engine Management update applied. I don't think that was the cause as my codes were read last year and the AA man said there was a low reading on one of them. MB are still replacing them FOC, even out of warranty, if certain conditions are satisfied. There have been a number of revisions of these sensors, but they are still failing.

Ernie

 

[paul243]

Thanks Ernie, interesting.
I'm glad that it was spotted by the dealer or I would have been paying £1000 plus at my indie, although I do have a warranty from the dealer where I bought it used, not sure if it would have been covered though.
Did you have any symptoms?, I had none except the fuel consumption was high but I put that down to it being a 350?
Did you notice any difference in performance after the software update?