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Discussion Starter #1
A few days ago while driving the CEL light came on. Rather than pay a mechanic $100+ for a diagnostic code I purchased the

BAFX Products 34t5 Bluetooth OBDII Scan Tool for Android Devices $20

Paired it with the Torque Pro app $4.95

to do the diagnostics on my own. It shows codes:

P0030 HO2S heater control circuit bank 1 sensor 1
P2237 02 sensor positive current control/circuit open bank 1 sensor 1
P0050 HO2S heater control circuit bank 2 sensor 1
P2240 02 sensor positive current control/circuit open bank 2 sensor 1
P2006 Intake Manf runner stuck closed bank 1 a)

I did some research and the first four codes deal with the 2 upstream oxygen sensors. It does not seem very difficult to replace them for around $120 each plus the special tool you need to remove them around $20.

Before I go that route though I found some information stating that the fuse for these sensors may be blown. The problem is I dont know which fuse to check. In the fuse chart there is no listing for Oxygen sensor fuses. The only ones that would seem to apply are for "Engine Management". I checked out all five listed under engine management (although to my surprise one was missing all together.) I replaced it and the others were fine.

So my question is: Does anyone know which fuse to check for the upstream (pre cat. converter) oxygen sensors? Anyone had any experience with similar issue and how it was resolved?

The P2006 code is a different beast. Anybody have any experience with this issue?

Feedback greatly appreciated.

Thanks.
 

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Clear the codes and the CEL should go off. Drive the car a day or so to see if it come back on. Recheck the codes. Sometime there is a one time quick happings that will create an error code. If it come back on and you get the same codes again then replace O2 sensors.
 

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I suspect the codes are related and have to do with the P2006. This is a flap system that redirects the incoming air between two paths into the engine. There is a bell crank on the front of the intake the controls them. It is plastic and common to break.

Unfortunately, your OBD code reader does not provide the additional information that the MB Star system would provide that would help to further understand the codes and the commonality between them if any.

My advice would be to first do a search on this site on repair issues/options on the P2006 code and when it has been fixed and all codes have been cleared see if the O2 sensor codes come back or not.
 

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Just FYI, the O2 heaters (not the sensors) are powered via wiring sleeve/solder joint Z7/36, which also powers lots of other engine components, including AIR pump, intake runners and the tumble flaps (which mchild mentioned are related to P2006). Front SAM Fuse #54 supplies +12V to this sleeve. If there were a fuse problem there, I would expect lots of other codes from lots of other components.

The P2006 is a well-known issue and you should determine if your lever is broken before assuming all these codes are related.

The O2 sensors (not the heaters) receive power from the ME.

The O2 heaters/sensors have connectors at the bottom-rear of the transmission - have you had any transmission work done lately, or hit anything that might've knocked them loose?
 

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Discussion Starter #7
Thanks. I checked #54 and its ok. So i dont think its a fuse problem. I reset the CEL and ran diagnostics again and now only the P2006 and P2240 faults show up. The CEL has not lit up. I will drive around for a few days to see what happens.

Thanks for your help and suggestions.
 

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Hi folks, my car is 2004 SLK350 R171. I am suffering same problem with exactly the same fault codes (i.e. P0030, P2237, P0050, P2240 and P2006). Both O2 sensors were replaced together with a brand new fully charged battery but same fault codes come again no matter how many times I cleared. All cable and harness are visually checked fine. Any suggestion on the repair or any chance of failed ECU?

Thank you in advance.
 

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Hi folks, my car is 2004 SLK350 R171. I am suffering same problem with exactly the same fault codes (i.e. P0030, P2237, P0050, P2240 and P2006). Both O2 sensors were replaced together with a brand new fully charged battery but same fault codes come again no matter how many times I cleared. All cable and harness are visually checked fine. Any suggestion on the repair or any chance of failed ECU?

Thank you in advance.
this thread is 2 years old
you might want to start a new thread
 
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