C250 CDI First Time Mercedes Owner Needs Help

[DAVID JAMES]

Hi all. Recently purchased a 2009 Mercedes C250 Cdi which I absolutely love, however it took only 2 weeks into owning until my issues started.

I am by no means a mechanic, hence taking my car to a independent Mercedes specialist.

So far the car has had a new battery and 2 O2 Sensors replaced but the same codes keep coming back along with the engine management light.

Codes are :
P208000 - Temperature Sensor 1 Exhaust System (Cylinder Bank 1) Has a malfunction.
P208064 - Temperature Sensor 1 Exhaust System (Cylinder Bank 1) Has a malfunction. There is an implausible signal

Once the light comes on, the car goes into a limp mode in which it loses substantial power. The mechanic who has been trying to resolve the issue has been good as gold but is unsure on what to do next.

Any help would be greatly appreciated. Thankyou

 

[Diddles]

Has the temperature sensor been replaced? If not it needs to be replaced.

 

[DAVID JAMES]

Yes, invoice states "Replaced Exhaust Gas Temperature sensor upstream of turbo and cleared codes".

 

[Diddles]

Normally replacing the sensor should do it. Is it a genuine mercedes part? Maybe the wrong sensor has been changed. This is what the sensor looks like.

 

[DAVID JAMES]

Yes he said they only used genuine parts. I asked him to change it again which they did reluctantly but within a week the codes came back. On the next visit he cleaned all connection to the ECU and cleared the codes which again worked for approximately 8-9 days before the codes came back with the EML.

 

[steveq]

Hi,

Can you look to see what the values that the sensor is returning?
I have a iCarsoft 980 which will show the values that the sensor is reading. When the car is cold the sensor temperature is close to the outside temp and when the car is up to normal working temperature the sensor shows about 140deg C.

When mine went faulty the temp shown was 280deg permanently.

 

[DAVID JAMES]

I will need to get a code reader. I have got the CReader 129 but i cant see the temperature of the o2 sensors. I was looking to buy the Autel MD808 Pro so I can use it for lots of cars rather than just mine. What is generally considered the best code reader upto a maximum £350. Once I have one I will check those temperatures and see whats happening.

 

[Diddles]

The o2 sensors are different parts to the temp sensor. Hopefully the temp sensor has been replaced and not the o2 sensor.

 

[DAVID JAMES]

Sorry, I think i'm getting confused, just checked the invoice and it was the exhaust temp sensor that was replaced. Part Number: A0009056804

Also had Part Number : A0009056404 replaced

 

[Diddles]

Just checked the part number and its the right part. I cant help you at the moment but will ask someone I know tomorow for you and see if they have any ideas.

 

[DAVID JAMES]

Brilliant thank you Diddles!

 

[steveq]

I will need to get a code reader. I have got the CReader 129 but i cant see the temperature of the o2 sensors. I was looking to buy the Autel MD808 Pro so I can use it for lots of cars rather than just mine. What is generally considered the best code reader upto a maximum £350. Once I have one I will check those temperatures and see whats happening.

I suspect that it isn't possible to get a reader that will read all codes from all manufacturers. The iCarsoft V2 , which is their latest model, seems to have about 20 different variants that each cover one car manufacturer.
That said, I am not familiar with the Autel model you mention.
I have a basic Autel OBD II reader and it is fine but doesn't show anything like the detail that the iCarsoft i980 shows for a Merc.

My iCarsoft i980, which is Mercedes specific, will read non-Merc OBDII but won't give as much detail as it does for Mercs. Probably much the same as your current reader does for your Merc.

 

[DAVID JAMES]

Hi Steveq, I have now ordered the iCarsoft i980 which should arrive on Wednesday. I will then check the live data then. thanks again for your help.

 

[DAVID JAMES]

Hi Steve, I have received the iCarsoft i980 today. Are you able to guide me on what i need to do to get the values for the correct sensor please.

 

[DAVID JAMES]

Hi Steve, I have received the iCarsoft i980 today. Are you able to guide me on what i need to do to get the values for the correct sensor please.

I have gone to livestream and it shows me Bank 1 Sensor 2?

 

[steveq]

Hi,

On your i980:-
Select Diagnose
then Benz
then select your car -- C Class 204
then select your exact model (mine is a 204.002 -- your C250 will be different 204. -- it is part of your VIN)
then select right hand drive & auto/manual
That will show you all the various sections of your car that are available.
Select the first one on the list which is the Electronic aspects of the OM651 engine.

Then select 'Actual Values'
That will show you many options.
The ones you want are either the 'Check boost option control' or 'Limitation of engine torque'. They are the 6th & 7th in the list on mine.
On either of these the 'B19/11 Temp sensor upstream of turbocharger' is the value you want. Scroll down to see this if it isn't on the first screen display.
Mine is showing values varying between 135 and 167 Deg C.
When the engine is completely cold it shows the ambient temperature.

Previously, when it was faulty before I replaced it, it was showing 250 Deg C permanently.

Best of luck.

 

[DAVID JAMES]

Hi,

On your i980:-
Select Diagnose
then Benz
then select your car -- C Class 204
then select your exact model (mine is a 204.002 -- your C250 will be different 204. -- it is part of your VIN)
then select right hand drive & auto/manual
That will show you all the various sections of your car that are available.
Select the first one on the list which is the Electronic aspects of the OM651 engine.

Then select 'Actual Values'
That will show you many options.
The ones you want are either the 'Check boost option control' or 'Limitation of engine torque'. They are the 6th & 7th in the list on mine.
On either of these the 'B19/11 Temp sensor upstream of turbocharger' is the value you want. Scroll down to see this if it isn't on the first screen display.
Mine is showing values varying between 135 and 167 Deg C.
When the engine is completely cold it shows the ambient temperature.

Previously, when it was faulty before I replaced it, it was showing 250 Deg C permanently.

Best of luck.

Hi Steveq, thanks for that brilliant post. Will check in the morning before I leave for work and then again when I get there. Thanks again for your help.

Sent from my CLT-L09 using Tapatalk

 

[DAVID JAMES]

Ok, so connected up this morning and tried the above:

On your i980:-
Select Diagnose
then Benz
then select your car -- C Class 204
then select your exact model (mine is a 204.002 -- your C250 will be different 204. -- it is part of your VIN)

Mine is a 204.003

then select right hand drive & auto/manual
That will show you all the various sections of your car that are available.
Select the first one on the list which is the Electronic aspects of the OM651 engine.
First one in the list for me is :

Motor Electronics 'CDID2' (See Screenshot)

I don't have the option 'Electronic Aspects of the Engine'

I have checked in FSCU Control unit Fuel option and lots of the other options, but can't seem to find anything other than
' Catalyst Temperature Bank 1 Sensor 2 ' which, I don't think is related to the error code i get.

I have scrolled through lots of the options but cannot find
'Limitation of engine torque'
'Check boost option control

I have attached some pictures.

Thanks again.

 

[DAVID JAMES]

Just went out to the car to try again and read codes. This time a new code has come up.

P0236 Generic Pending

TurboCharger/Supercharger Boost Sensor A Circuit Range/Performance

 

[steveq]

Ok, so connected up this morning and tried the above:

On your i980:-
Select Diagnose
then Benz
then select your car -- C Class 204
then select your exact model (mine is a 204.002 -- your C250 will be different 204. -- it is part of your VIN)

Mine is a 204.003

then select right hand drive & auto/manual
That will show you all the various sections of your car that are available.
Select the first one on the list which is the Electronic aspects of the OM651 engine.
First one in the list for me is :

Motor Electronics 'CDID2' (See Screenshot)

I don't have the option 'Electronic Aspects of the Engine'

I have checked in FSCU Control unit Fuel option and lots of the other options, but can't seem to find anything other than
' Catalyst Temperature Bank 1 Sensor 2 ' which, I don't think is related to the error code i get.

I have scrolled through lots of the options but cannot find
'Limitation of engine torque'
'Check boost option control

I have attached some pictures.

Thanks again.

Hi,
On the "Electronic aspects of the OM651 engine" -- I was typing this from memory (obviously flawed).
I thought it did say "Electronics" & "OM651 engine" but I won't be able to confirm that until this evening. The rest of the post is accurate (I wrote notes down when I was in the car with the i980 attached for everything apart from that one line).

Anyway -- select the first option on the screen whatever it says and then do the rest:-
Then select 'Actual Values'
That will show you many options.
The ones you want are either the 'Check boost option control' or 'Limitation of engine torque'. They are the 6th & 7th in the list on mine.
On either of these the 'B19/11 Temp sensor upstream of turbocharger' is the value you want. Scroll down to see this if it isn't on the first screen display.

Separately -- I did have a slight concern when I wrote the original piece as to whether you actually have the OM651 engine. I know it was introduced in 2009. The first 3 digits of your engine number on your registration documents will have 651 if you do.