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

[merc85]

as i thought <MB are usually very competitive battery wise and on tyres too

Deffo Oe is the right choice

 

[Alex5000]

as i thought <MB are usually very competitive battery wise and on tyres too

Deffo Oe is the right choice

Yep, I think you are right.

Does anyone know if the new level sensor needs to be coded or anything like that? I’m going to refit the original otherwise as I don’t understand why an intermittent dash warning has progressed to a permanent one if the new sensor is correct/working.

 

[merc85]

No coding required, level sensors are quite cheap also, Febi do them,

Think mb number A2115427717

 

[Alex5000]

No coding required, level sensors are quite cheap also, Febi do them,

Think mb number A2115427717

Thank-you, good to know. That is indeed the part number I have ordered. Unfortunately it must be faulty, or I’ve disturbed something; but I’m beginning to think it isn’t the sensor that was causing the original problem. I’ll change back to the old one, fit the new battery, check the codes again and report back.

 

[Alex5000]

I confirmed the battery is indeed from 2011. I made it out as 18-04-11 on the label but it was mega-faint, I had to tear it off and pass it through light to make it out. The extensive history does however show a battery fitted at the dealer in May-11, so it ties up.

 

[W1ghty]

Yep, I think you are right.

Does anyone know if the new level sensor needs to be coded or anything like that? I’m going to refit the original otherwise as I don’t understand why an intermittent dash warning has progressed to a permanent one if the new sensor is correct/working.

I confirmed the battery is indeed from 2011. I made it out as 18-04-11 on the label but it was mega-faint, I had to tear it off and pass it through light to make it out. The extensive history does however show a battery fitted at the dealer in May-11, so it ties up.

Is there a date stamp on the terminal as well ?

 

[Alex5000]

Is there a date stamp on the terminal as well ?

I know someone else mentioned it, but I’ve only just looked properly. It’s stamped 0411, so likely April 2011, or could be the forth week of 2011 if they do it like tyres. Either way, triple confirmation that its a 2011 battery.

 

[E55BOF]

Fourth week of 2011. Mine was 23something.

 

[MJJ]

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.'

I had this fault on my S211, and mine was parasitically draining the battery every 48 hours - would be down to 10v after this length of time.

Root cause was the alarm siren located within the inner front wing, driver's side, behind the plastic wheel arch liner. It has a rechargeable battery that is long since toast at c. 13 years old. Because the car is constantly trying (and failing) to charge that battery, it keeps the CAN network awake and drains the battery.

I posted about it here, perhaps it helps.

These cars throw up lots of spurious errors when the batteries are weak, mainly because (I think) the battery voltage drops so low after cranking that the sensor readings go outside of programmed tolerances. I would solve the parasitic drain (assuming yours has one too), and fit a new battery first.

Martin.

 

[Alex5000]

I had this fault on my S211, and mine was parasitically draining the battery every 48 hours - would be down to 10v after this length of time.

Root cause was the alarm siren located within the inner front wing, driver's side, behind the plastic wheel arch liner. It has a rechargeable battery that is long since toast at c. 13 years old. Because the car is constantly trying (and failing) to charge that battery, it keeps the CAN network awake and drains the battery.

I posted about it here, perhaps it helps.

These cars throw up lots of spurious errors when the batteries are weak, mainly because (I think) the battery voltage drops so low after cranking that the sensor readings go outside of programmed tolerances. I would solve the parasitic drain (assuming yours has one too), and fit a new battery first.

Martin.

Thanks that is very useful information. I though I read that the alarm siren had been replaced on mine, but checking back, I have no record of it - I'll pull off the arch liner and check the date on it at the weekend. I remember AMGmeister did the siren on his car - I may go back and rewatch that video.

You are dead right about battery voltage dropping causing codes to be triggered. I'm going to pick up a new battery at lunchtime.

 

[Alex5000]

A short update on this one. On the guidance from many of you who have commented, I swapped in a new battery before Christmas and have run the car around a few times. Scanned it this morning and a whole host of codes logged, but most look like they were as as a result of the battery change.

I cleared everything, scanned it again and went for a short run. I have had just three codes pop back up:

• Communication with component B33 (ATA inclination sensor) is interrupted.
• B31 (C-AAC multifunction sensor) - If I interrogate the readings it's showing little hazard signs next to all of the values. As simple as replacing the sensor?
• No CAN message 'Terminal 61' from control unit A1 (instrument cluster). If there is no specific customer complaint, ignore fault code - *Shrug*

After clearing the codes the first two came straight back when scanning the car again. Fuel door still won't lock, and the parking sensor issue remains (not surprised, although no fault logged). I've cleared everything once more and have a 150mile round trip at the weekend so I'll see what comes back after a long drive.

A few questions for now if anyone out there can help:

1. Where is the 'B33 ATA inclination sensor' located?
2. Where is the 'B31 C-AAC multifunction sensor' located?
3. Anyone have a guide on how to replace/access the fuel door actautor on a S211? It looks like quite a bit of trim needs to be removed. Do you have to do this blind?

Thanks to everyone who has commented so far. I haven't checked the alarm siren date yet, but I did check the auxilliary battery and the only number on it which looks like a date ended in 09, (nothing on the terminals, this number was on the longer side facing forward) so could be that is well past its best too. It read 12.3/4V just like the main battery. If it isn't too dear I might just replace this too.

 

[mersum1es]

B33 is in rear cargo are, right side under trims.
B31 is engine bay, under windshield depending on engine (you have not specified on avatar more car info) which side. Use google search, might find it, difficult to explain without picture

 

[Alex5000]

B33 is in rear cargo are, right side under trims.
B31 is engine bay, under windshield depending on engine (you have not specified on avatar more car info) which side. Use google search, might find it, difficult to explain without picture

2004 S211 E55 AMG

I have updated my avatar

 

[Alex5000]

I did 150miles at the weekend Essex-Norfolk return and the car felt fine although a few issues remain. I also got an airmatic warning when I raised the suspension to go up my parent's driveway, then on the drive home the ride was noticably harder. Scanned the car and I have the following all of which I had reported and then cleared before the run. Which is good at least for consistency:

• 9059 *Stored&Current* Communication with component B33 (ATA inclination sensor) is interrupted.
• 9450 *Stored&Current* B31 (C-AAC multifunction sensor) - CO & NOX both 1024, Dewpoint -31C, rel humidity 255%, current ambient temp 39C (ambient temp was ~15DegC at the time of scan)
• 9034 *Stored* No CAN message 'Terminal 61' from control unit A1 (instrument cluster). If there is no specific customer complaint, ignore fault code

I also now have a couple of new ones:

• 9012 *Stored* RWT-Rear-end door control module - Component A72 (Rear door locking unit) is faulty or the line to the component has a short circuit or open circuit (The Hall sensor of the rotary tumbler is defective.
• 5101 *Stored* AIRmatic B24/3 (Left front body acceleration sensor) : Zero point variation - Accompanied by a airmatic visdit workshop dash wanring - B7 airmatic pressure sensor reads 10.29bar. Sensor reads 2549mV - It was the B22/3 rear axle level sensor which was triggering this dash warning before.

The following faults exist which I've noted so far and might be relevant.

• AIRmatic firmer than expected after AIRmatic dash warning displayed (on suspension ride-height adjustment activation) - even before than the ride seems firmer than I would expect for a car on air, although I have no idea what it should feel like when new.
• Fuel door still won't lock
• Parking sensor issue remains - as before I think this is likely a failed sensor, I will likely just go-ahead and replace this
• Passenger door mirror fails to dim like drivers side mirror and rear-view mirror do

Any thoughts welcome on where to begin fault finding now I have discounted the battery as a source of issue. Do these issues point to a particular module or section of harness?

 

[mersum1es]

Like said #8, passenger side mirror WONT dim in any Mercedes.

Acceleration sensor fault will put aimatic to 'limp' mode where it is at hardest set, or sometimes even drives all struts to upper end position.

Check rear sam for water damages, some of the faults are driven by rear sam.

 

[Alex5000]

Like said #8, passenger side mirror WONT dim in any Mercedes.

Acceleration sensor fault will put aimatic to 'limp' mode where it is at hardest set, or sometimes even drives all struts to upper end position.

Check rear sam for water damages, some of the faults are driven by rear sam.

Thanks for that. I must have missed post #8.

At a glance the rear SAM looks dry and none of the fuses are blown. I'll investigate further...

 

[Alex5000]

Just came back to close this one out in case anyone on or off the forum ever comes across this topic.

Battery drain:

Seems battery drain issues were down to the tailgate motor. It sounded weak and must have been trying to close the rear hatch even when it appeared shut. I replaced both batteries and the motor and haven't had an issue since. That also got rid of most of the codes I reported on, although B31 (C-AAC multifunction sensor) still remains but with no apparant issue.... A specialist told me 'they all do this' (re the sensor code). I did check the alarm siren, and that has never been replaced - This is on the to-do list.

Fuel door locking pin

The fuel flap was missing the actuator pin, so I got one of those with a motor for a tenner. Maybe a previous owner had had the actuator fail in the past and removed the pin - I couldn't find the original pin if it was there anywhere. Handily the actuator has a small key so you could wind the pin out manually if it did fail once you know where its located.

Ride quality

Regarding my ride issues, much of the issues seemed to be down to worn suspension joints. I ended up taking the car off the road over winter and doing a major overhaul, but I think a front track rod (barely perceptable) and rear lower spring arms heim joints (quite bad) were largely to blame, and some unbranded front thrust arms probably didn't help. Lastly the front drivers wheel bearing was slightly loose and was causing an intermittant speed dependant vibration which after a very slight tighten has disappeared - there was perceptable movement in the wheel with it raised, but no mention on the MOT. There was nothing wrong with level sensor or the rest of the airmatic system like I thought before, that all seems to have been battery related.

Overall, suspension is now much tighter, and the difference between Comfort Sport I and II is at least noticable. I got the car aligned locally, and I would like to get it redone at my workshop of choice but they have a long wait and I just haven't round to it.

Parking sensors

Traced down the failed ones and replaced


Thanks to everyone who answered the thread, you contributed to me resolving the problems. Very little else wrong with the car now; a few things to do, but otherwise driving and enjoying it.