S211 - Airmatic visit workshop - B22/3 rear axle level sensor (together with a whole host of other codes).

[Alex5000]

The ride on my S211 seems pretty firm, switching suspension modes doesn't seem to do anything (although the car will raise and lower ok, it is lower on one side), and a couple of times the 'Airmatic visit workshop' symbol and message would pop up intermittantly.

This prompted me to scan the codes with a basic scanner and I'm getting a host of codes, including B22/3 rear axle level sensor. I have run the car around a few times after clearing the codes, but this one always reappears - I'm also getting codes for:

Interior protection reports a fault in the glass breakage loop
B31 C-AAC multifunction sensor
error in serial communication to rear lamps and interior motion sensor. No response from component N70/2b1 (interior protection sensor) - The interior motion sensor is also listed as 'not activated.'
communication with B33 ata inclination sensor is interupted
outside air temp sensor

There were also a few others I didn't record (I only borrowed the scanner) related to air con, the passenger seat heating element and the tailgate motor, (that last one I have replaced (and it was solved)

I have also noticed the fuel door will not lock, the front A/C display intermittently remains dim, passenger door mirror won't dim, and I have a failed parking sensor (front drivers side immediately next to the numberplate, and the sensor has corrosion on the face, which I believe is causing the PDC to randomly come on). In addition I had a random battery drain one day which has since prompted me to hook up a trickle charger ever since - not ideal.

I list all these in case they are relevant, and I will get to the bottom of all of them, but starting with the airmatic issue, I thought it would be straightforward and just replaced the sensor with a VEMO part from Autodoc. I seem to be in a worse state now as the car feels exactly the same but the airmatic warning illuminates on the dash every time the car is started. The readouts from the old sensor were normal I believe but the code suggests the signal was interupted (which kept the car in safe mode) logging a code each time.

If these faults all point to one module it might explain some/all. I'm going to borrow the scanner again as soon as I can, does the new sensor need to be coded/reset? I've tried to get to the bottom of this with searches, but a bit lost at the moment. Please help if you can

Cheers

 

[W1ghty]

The level sensors metal arms can rust and break , they are about £30 from MB so check them as well .
My other thought is that MB’s hate low voltage , how old is the battery , date stamp is on the terminal . What charge is it showing , if you double press the dash reset button with the key in position 1 it should show battery voltage ?

 

[Alex5000]

I replaced the sensor, the arm was intact.

Car is connected to a trickle charger, so it’s not seeing low voltage. I’ll check the date regardless. It did flatten itself to 4v overnight (maybe a few nights) once (how I discovered I hd a drain) but has recovered so that it reads at least 12v on the dash if left overnight uncharged now.

 

[AntMB]

Air suspension, nice idea when working, but after a few issues I got rid of mine and converted to coil springs, though mine was just the self levelling rear.

 

[grober]

your problems do sound electronic in nature- bad connections, shorts, leakage to earth, low voltage---- check the boot area for damp/ water leaks-especially the rear sam [ fuses and relays] unit behind the trim

 

[W1ghty]

I replaced the sensor, the arm was intact.

Car is connected to a trickle charger, so it’s not seeing low voltage. I’ll check the date regardless. It did flatten itself to 4v overnight (maybe a few nights) once (how I discovered I hd a drain) but has recovered so that it reads at least 12v on the dash if left overnight uncharged now.

The battery is pretty dead or dying at 12v buddy , especially in the winter

 

[Alex5000]

It was a while ago I measured it. i’ll pull the charger off it and see what it drops to over the next 24hrs.

 

[mersum1es]

Passenger mirror won't dim.

 

[Railwayman]

As grober said, sounds like bad earthing or similar "simple electrical fault", only advice I can offer is to pick the most basic faulty circuit and work to solve that which will most likely solve them all.

 

[Alex5000]

I pulled the trickle charger off at 1230 today and at 1900 the car is still showing 12.3v on the dash. I’ll check at 1230 tomorrow. Checked the battery and it is dated 2011. Although I can’t be sure as the label is heavily worn away. p/n: A0055411001

 

[grober]

I pulled the trickle charger off at 1230 today and at 1900 the car is still showing 12.3v on the dash. I’ll check at 1230 tomorrow. Checked the battery and it is dated 2011. Although I can’t be sure as the label is heavily worn away. p/n: A0055411001

At 10 years old its way past its sell by date----it may not be the battery causing your fault---but a good battery will eliminate a lot of spurious fault codes and help track down your problem-after 5 years a new battery is never a waste

 

[Alex5000]

Now that I think it, before I started using a trickle charger, I used to sometimes get the dash message on a cold start about some convenience functions inactive - sure telltail the battery is weak? Or maybe that I have a battery drain...

How can I tell if it is an AGM battery? (The ECP choices for my plate are all AGM) Will a new battery need to be coded?

£232 for an Exide AGM battery with a 3-year guarantee.

 

[Alex5000]

A quick VIN decoder suggests I have option 673 - High capacity battery

 

[E55BOF]

A new battery won't cure your Airmatic fault, but at ten years old, yours is unquestionably past its best. These cars are very sensitive to battery charge state, and a failing battery will cause all sorts of apparently unrelated electrical problems and codes.

The parking sensor face is plastic, so it cannot be corroded.

How old is the car? I rather doubt all the 211s had AGM batteries; ignore ECP and look on eBay.

What does it say on the battery regarding the spec - CCA, AH and so on? You can replace it with an equivalent Varta (the OE manufacturer anyway), four year warranty and next day delivery if ordered early enough, for about £170 from Tayna or Battery Megastore, to mention but two, but measure yours and check their application listings to see if they are physically the same size. (I had one for my CLS from Battery Megastore, and their application listing was wrong. They delivered a (correct) replacement the following day, no quibbling, and collected the wrong one.)

A non-AGM will likely be about £100. If you're not planning to keep the car for long, you might consider fitting a cheap battery; up to you.

 

[Alex5000]

It is an 04-plate E55, I’ll take a note of the battery specs, but always a chance the wrong battery is fitted; so I would like to reassure myself what the correct one should be per build, and like I said option 673 should be fitted.

I’m restoring the car properly and I want to fit a quality battery. Thankyou for the tips, I’ll check both those sites.

If it isn't corrosion on the parking sensor its bubbling of the paint. Either way possible cause of failure, and it is the only one which doesn’t trigger the dash lights and audible warning.

 

[merc85]

Pop into Mercedes Waterhouse Chelmsford , ask for Andrew Gerrie, they will sort it properly at a reasonable price.

 

[Wearsthefoxhat]

I replaced the failing battery on my 05 E55 four years ago. The guy on at the MB parts counter gave me an AGM one as per the vin and it replaced a four year old AGM one. Thinking of getting a SLA one this time as this one is beginning to show signs of failing…

 

[W1ghty]

My 2008/09 E320cdi is an AGM battery, best price I got was from MB Grangemouth (they deliver for £5 ish) and give a discount if you mention the forum

 

[merc85]

Just to note,

We retail a Varta 019AGM 12V 95AH 850CCA AGM SS PLUS 3YR at £190 inc vat

But unable to deliver unfortunately, we are in Harwich essex,

Have you tried MB Waterhouse for a price? you may be surprised

 

[Alex5000]

MB battery: £169.60
Varta G14 from Battery megastore: £163.95
Varta G14 from Tayna: £164.47

Given the minor price difference I would probably go for the MB part.

The existing battery was flickering 12.3/12.4v today after 24hrs standing, was reading 12.3v at the same time yesterday (I haven’t driven the car). Loathed to change it if it is ok, but I understand its probably necessary at this age. I’ll check it again tomorrow.

I briefly pulled the trim off in the boot and checked the rear SAM. Nothing looks messed with, and all the fuses looked intact at a glance, no signs of moisture.