The car leans to the left. The left airbag deflates and the right one was just replaced. So I order a new bag, and a canbus scanner. The scanner shows a fault with the right level sensor. I clear the codes and read the left level sensor voltage (the right level sensor is not shown on the scanner). so while I am waiting for the bag, I replace BOTH sensors. The right sensor still does not show up on the scan and the right bag inflates overfilled.

What happened to the right level sensor?
There is no sensor on the scanner. Only the left sensor shows.

 

I just bought an '08 R320 which had a Strutmasters spring conversion (rear Self Leveling not all 4 corners ADS).

In a fit of stupidity and pigheadedness I decided to retro fit the rear Airsprings to factory spec the car, just for the hell of it and because I saw them for £80 quid for the pair on Ebay,

After checking out as much as I could it seemed as though the existing parts were all in good order, based mainly on blind faith, Google and a good deal of optimism.

So I put Airsprings in (properly 'Winged it' and so far its turned out too good to be true; i.e its all working great, and for £80!).

But one very confusing aspect was getting the thing to initialise (remember that I was clueless and didn't know what to expect),

Whilst only having the more basic diag scanner Carsoft i980, which did indeed, as you say - only seem to present the rear left level sensor?!

I even swapped the sensors around (they seem to be fully interchangeable) and no conclusive change in results, with only ever one sensor showing up in the scanner.

I did occasionally get a reference to the right level sensor which seemed to indicate a fault, but the two sensors never appeared together and generally the left sensor seemed to be the one that appeared with a positive reading, suggesting it was good?

Either way after a good deal of faffing I sort of established that by carefully lowering the car in a way that did allow me to line the airsprings up to marry with the mounts and then let the sensor/sensors report a 'too low' reading to the suspension ECU - the car then did a correct initialisation/inflation cycle and inflated both airsprings correctly;

So most importantly there was no need to have the system reset or configured by MB using a Star scanner etc.

(Actually the first time of asking, because I finished the job in the dark and one airspring wasn't seated properly, it inflated in an L-shape! and I had to remove it, heat it up with a hair dryer and roll the rubber back onto the airsprings bottom most moulding section, whilst using extreme effort and profanity, but I'll keep quiet about that and make out it was all slick 'n' skillful...)

Long story short - so far it appears that the suspension right & left level readings may not report as hoped using certain scanners, so swapping the rear sensors between the two sides may be the only way to do any 'cheap' kind of testing on them, other than perhaps a multi-meter test perhaps? or of course the ever popular trip to the MB dealers to be fleeced, again...

Cheers,

Steve.