O2 Sensor issue on 2006 C209 CLK 320 Cdi

[seymansey]

I thought i'd add my experiences here for the benefits of existing users and googlers.

Purchased a 67k CLK 320CDi. Car drove great, but when I plugged in a diagnostic reader (Autel unit), i had multiple o2/lambda upstream errors regarding voltage, etc. I do regular very long motorway drives and coudln't get the MPG past 41mpg, no matter how hard I tried. Car felt pretty responsive to drive, and i've read on numerous threads that the OM642 seems to dine on these sensors and it wasn't much to be concerned about. Anyway, i like my cars to be error free so decided to fix it.

Purchased a new o2 sensor. On this model, it's located under the car, just by the gearbox bellhousing, under the middle underbody cover. Very easy to remove with a 22mm spanner. (Cost for the bosch sensor was £128 from ECP). About 40 mins in total.

After fitting and clearing codes,the difference was immediate. Car pulled a lot 'cleaner' and stronger and more importantly I managed to average over 47mpg on my 100mile journey this weekend.

Hope it helps anyone who has similar issues.

 

[t-dawg1]

What exactly were your O2 sensor errors as iv have these on mine all 02 sensor voltage and 1 glow plug module voltage etc. did your car have hard starting issues from cold or did it always start 1st time from cold? Mine is the OM642 V6 on a w211 E280

 

[seymansey]

I was getting the following off the diagnostic reader:

2030 CHECK COMPONENT G3/2 (o2 SENSOR UPSTREAM OF CAT OPEN CIRCUIT)
2038 CHECK COMPONENT G3/2 (o2 SENSOR UPSTREAM OF CAT RESISTANCE TOO SMALL)
2195 HEATING CHECK COMPONENT G3/2 (o2 SENSORUPSTREAM OF CAT SIGNAL LINE INTERRUPTED)

But mainly error 2195 ( I reset the codes a couple of times to check and this persistently came back).

The car always started perfectly from cold - which I would expect it to anyway as the O2 Sensors aren't used during startup. That would be related to your glowplugs.

When I removed the sensor, there didn't appear to be much wrong with it visually. If i hadn't plugged in the reader, I wouldn't have noticed a problem with the car, no excessive black smoke, etc.

 

[t-dawg1]

These are codes I read

P2245 02 sensor reference voltage circuit low
P0131 02 sensor circuit low voltage
P0030 heater control circuit
P2239 02 sensor positive circuit control circuit high
P0670 glow plug module control circuit
P0130 02 sensor circuit
P0135 02 sensor heater circuit
P1101

Car runs very well jut that cold start issue and these stored codes which I cleared and keep coming back! Should I go to the dealer?

 

[SL300-24]

t-dawg1
On mine when the glow plug module went it blew white smoke on start up and would spin over longer than usual before starting.
I had the P0670 code saying that the glow plug module was open circuit, hope this helps.

 

[t-dawg1]

SL300 you have just solved my problem,yes mine blows white smoke on startup now and takes longer from cold to start. I'm going to get a new glow plug module in Thursday from the stealers and install it myself as it looks straight forward to change. Thanks so much for that

 

[Andy67]

Autel Unit

Which Autel unit are you using, I think I want to buy one,, whats the cost of your unit,, have seen Autel Ms509 for £33.

Thanks andy

 

[t-dawg1]

Which Autel unit are you using, I think I want to buy one,, whats the cost of your unit,, have seen Autel Ms509 for £33.

Thanks andy

What do you mean mate?

 

[Ian Donkin]

Interesting thread as mine is presenting upstream O2 sensor error messages and my economy over a pretty standard weekly 200 mile each-way journey has never been so bad. It was down on expected bhp on the rolling road too recently so I'm encouraged by your experience here.

I'll report back once changed.

 

[Andy67]

I mean which Autel unit do you use to test for error codes

 

[SL300-24]

Mine also shows an upstream o2 sensor code and I have always ignored it because everything seems to run fine, I think that I will sort it now.

t-dawg1 it is very simple to replace, takes about 20 minutes.

Andy I use the Autel 509 cheaper here....

http://www.amazon.co.uk/dp/B001LHXTO0/?tag=amazon0e9db-21

 

[t-dawg1]

I use this app on my iPhone it connects through wifi to an OBD connector

View attachment 39027

 

[seymansey]

Sorry for the delay in reply. I use this device, which has Mercedes specific modules:

Autel 7-Series Code Reader (JP701 / EU702 / US703 / FR704) with software CD

Works on lots of other makes too. Can read and reset autobox and airbag codes too.

 

[cosmograph]

Hi seymansey.

Can you confirm this is definitely the upstream sensor you have changed?, as I am having the same problem with my 2009 CLK320CDI and the only o2 sensor you can see under the middle of the car by the gearbox is the downstream one (post cat). Do you have to remove the middle cover and then look up into the recess to get access to it? It doesn't look easy or accessible at all.

 

[dundeepeh]

I asked the same question as yours on a different site, the answer I got there is only the one o2 sensor , the one in the middle of the car. I also have a clk320 cdi. Hope this helps

 

[isohail72]

T- dwag1 Mate the connector does it connect through bluetooth?

 

[t-dawg1]

T- dwag1 Mate the connector does it connect through bluetooth?[/QUOTE

No it uses a wifi signal,once it's plugged into the car it sends a wifi signal and once u start the wifi scan in your phone it picks it up and starts to sync with the car

 

[seymansey]

Hi seymansey.

Can you confirm this is definitely the upstream sensor you have changed?, as I am having the same problem with my 2009 CLK320CDI and the only o2 sensor you can see under the middle of the car by the gearbox is the downstream one (post cat). Do you have to remove the middle cover and then look up into the recess to get access to it? It doesn't look easy or accessible at all.

Yep, there's only one on the 320 cdi, and it's by the gearbox. For some reason the diagnostics sensor call it upstream, but in reality it's the downstream as its after the cat.

It's pretty easy to do, I did it with a pair of drive on ramps and shuffling about underneath.

 

[isohail72]

So i meed to buy wifi connector? From where i can buy that? Thx

 

[t-dawg1]

t-dawg1 On mine when the glow plug module went it blew white smoke on start up and would spin over longer than usual before starting. I had the P0670 code saying that the glow plug module was open circuit, hope this helps.

Just had some conflicting information about replacing my GLOW PLUG RELAY MODULE? Does the car need to be plugged into a STAR after this has been changed or can I just replace it at home? I'm about to undertake this job but Iv just had a guy say to me that it may corrupt the ECU if I just change it without using the star afterwards?