Intermited EWL -advice needed

[theogeor]

My 16 month old B180 Petrol (w246) has an intermittent issue where the engine warning light comes on. This has been going since the car was 3-4 months old and despite a number of visits to the MB garage and also calls to mobilo is still coming every now and then which is very frustrating.
As I have an OBDII BT diagnostic and relevant software I was able to capture it while it was there.. (Its P2626 - Powertrain O2 Sensor Pumping current Trim Circuit/Open bank1 sensor 1). Mobilo has also seen the same error when visited and provided it in their report
However every time we book an appointment and by the time we take it the problem is gone. We have explained that to our local MB service department but as they are unable to give us a slot intimately so as to have a look at it while is there we still nowhere near a conclusion. Last time we were told that Mobilo Tech should not have cleared it as that is the reason they cannot find it which is BS in my opinion (they had the report). I know that Star might give them more info but how on earth they expect to see an intermittent problem when they give my wife an appointment is 2-3 weeks away. Now is has done it twice the last 4 weeks and is getting more and more frustrating.
Other than that the car seams to work fine and has no performance difference with or without the error.
My suspicion is that the lambda sensor is the cause of this but as the car is in warranty why shouldn't the "expert" deal with it..

Any advice on either how to deal with this or what the root cause might be is more than welcome and desperately needed..


TG

 

[theogeor]

And a quick update.. After a bit of spirited driving the Engine Warning light is gone.. This is the second time I have tried that and worked. Thinking loud here I am wondering if EGR valve come into play somehow.

TG

 

[theogeor]

Anyone ????

 

[pembssurf]

Unlikely it's agunked up EGR valve on an car that new.

 

[Giantvanman]

My 16 month old B180 Petrol (w246) has an intermittent issue where the engine warning light comes on. This has been going since the car was 3-4 months old and despite a number of visits to the MB garage and also calls to mobilo is still coming every now and then which is very frustrating.

And a quick update.. After a bit of spirited driving the Engine Warning light is gone.. This is the second time I have tried that and worked. Thinking loud here I am wondering if EGR valve come into play somehow.

TG

Are you certain your petrol car is fitted with an EGR valve?

 

[theogeor]

Are you certain your petrol car is fitted with an EGR valve?

According to this document yes it does ..

http://www.aachener-kolloquium.de/china/wp-content/uploads/sites/2/2014/04/Vent_Daimler.pdf

TG

 

[theogeor]

And the problem appeared again this morning my wife tells me... very frustrating. ....

 

[theogeor]

And again tonight.. .Its now coming every few days... MB assistance on Monday checked everything but other than re-seating the connectors could not find anything else wrong with the car..

Time to take more drastic measures .... but before I do so anybody has any ideas ??

TG

 

[theogeor]

Here is the full diagnostic taken earlier this morning

E - Motor/Engine Electronics (MB: 2709010900)
O2 Sensor Pumping Current Trim Circuit/Open (Bank 1 Sensor 1)
Code: OBD03 P2626
Fault: The trimming resistor connection of oxygen sensor 1 (cylinder bank 1) has an electrical fault or open circuit. / Fault: O2 Sensor Pumping Current Trim Circuit/Open Bank 1 Sensor 1 no sub type information / Fault: LSUIAsig: O2 Sensor Pumping Current Trim Circuit/Open Bank 1 Sensor 1 no sub type information / Fault: The connection of the trim resistance of the lambda probe 1 (Bank 1) has an electrical fault or interruption. _ / Fault: The trimming resistor connection of oxygen sensor 1 (cylinder bank 1) has an electrical fault or open circuit. _
Code: P262600

 

[squeak333]

squeak

hi ive been following your problems with your motor, have you had it sorted, im still waiting for my b180 amg petrol to arrive.

 

[Trendy08]

Hi all,
I had this issue on my W246 (M270 engine) throwing up the P2626 error every few days and here is the solution that worked for me. Just signing up and posting to P2626 questions in the hope of being able to help others, as I know it could be frustrating. I have spent hours trying things and monitoring...

what worked for my case: cleaned the oxygen sensor CONNECTOR
- I simply unplugged it
- sprayed some contact cleaner on both connectors (I used a product similar to WD40, not really contact cleaner but it worked)
- wiped any excess with tissue
- plugged and unplugged a few times
- kept it secure in the clip (to prevent it from being loose due to vibration)
P2626 never happened again so far - 1month and counting

my B class is also just 2 yrs old, fantastic family car, but having the CEL come every few days on is not what I or any mercedes owner wants to see.

other things I have suspected (in hindsight, I believe none of these are the root cause)
a. only using premium fuel - always 98 instead of just 95 or using different brands
b. changing air filter - MAY HAVE HELPED - the day I changed this, I still got the P2626 - so in my case this was not the issue, but I'd recommend this be changed too - I can see the air/fuel ratio is much better after changing this
c. software update - MAY HAVE HELPED - I note that after this s/w update (done by a dealer), the CEL came on again after 1 day - so I thought this was not really the root cause, but it may have helped.

Hope this helps anyone having the P2626 issue on their mercedes.

Good luck all.