P2016 and P2085 - M112 2001 CLK 61,000 miles
 

I'm currently getting a Check Engine Light (CEL). After checking the codes, the code scanner gave the following values.

P2016 Self adaptation of mixture formation from bank1/2 of cylinder is at
P2085 max/min limit at part throttle

I cleared the codes and drove another 5 - 10 miles and the CEL came on again with the same values.

I'm new to the M112 (V6) CLK 2001. I understand the Mass Air Senors don't last long on the w112 engines.

Are these error codes normally the result of bad MAS or should I be looking somewhere else?

Thanks,
Russell

I just discovered ....
P2016 & P2085 are corrensponding codes for po170 & po173.

With that said, it could be anything from fuel pressure regulator, fuel pump, Air Mass Sensor, etc.

But since I changed the Air Filter the day the problem started and and since CLK's 2001 m112, from what I've read on the forums, are hard on Air Mass Sensors, I'm betting Air Mass Meter/Sensor.

I did check to verify that tubing and air filter housing are fastened corretly.

Please keep us informed; I have a 99 clk320 & the same cel problem started when I also changed the air filter.

If your code appeared after replacing the air filter be sure the tube from the AMM is tight to the throttle housing. I have seen the flexible section come loose on the hard section of the tube. This was particularly on a 430 but the concept is to have a sealed housing from the AMM on into the motor.

I checked the connections for the tubing on the Mass Air Sensor yesterday. I reconnected from the Air filter housing tub to the MAS and verified the other side of the MAS was not loose and reset the codes. I drove the car almost 8 miles before the CEL (Check Engine Light) reappeared.

The replacement MAS arrived today. I replaced the MAS and let the car idel for a few minutes then drove it really hard for about 5 miles. I have my fingers crossed - no CEL yet. If CEL reappears, I'll post a response - if not, the MAS fixed the problem.

Geeze! The new replacement MAS did not correct the problem. After I drove the car several more miles after work this afternoon, the Check Engine Light returned. :mad:

P2016 Self adaptation of mixture formation from bank1/2 of cylinder is at
P2085 max/min limit at part throttle

Since I dont have the tools to check the fuel pressure, and the mileage is 61,000, I'm going to proceed with changing the FUEL FILTER. It is my understanding the fuel filter on the 2001 CLK320 has the fuel regulator build into the unit. I don't mind "throwing" money at maintenance items.:confused:

I'll also planning to check the voltage values on the O2 sensors.

FYI.. I purchased this car because I was tired of working on my 400se all the time - Never a dull moment when you own a Mercedes

To analyse the problem you just have to get the adaptation numbers. You are exceeding a limit. The problem varies by what limt you are exceeding.

While unlikely to be your problem, you also need to reset the adaptations when you repair the problem.

Steve, as always, THANKS very much for your input and insight. I have a Trisco Palm Scanner ver 3.1 that I use with my older model MB, but I'm unable to get adaptions #'s. From what I can tell, I can only reset the error codes for various systems.

I'm really unhappy with our local MB dealership/service department, so it makes me cring at the thought of taking my car to them.

Steve, I must say I have great respect for your advice (I always read your forum posts) no matter what the topic! :) Do you think I should "punt" and swollow my pride and take the car to the dealer service dept for help? Or give the fuel filter a try 1st?

I'm a computer engineer by trade, not a mechanic, but I naturally tend to hang on to certain problems way to long and should call in the experts.

Russell, what's the latest with your problem; has it been solved? Please let us know.

I have ordered a AutoEnginuity OBD II OBD2 Windows Scan Tool & Dyno(USB) to use with my laptop computer. Hopefully with the new scan tool I'll be able to get more detail on what is causing the error code creating the check engine light.

I also returned the MAS that originally ordered because it appeared defective. After installing the new MAS, the car would hardly run by the end of the day. After further observation of the new MAS, it had a Vaseline substance dripping from the base of the wire filament. I reinstalled the old MAS and the car ran fine again.

I also have on order a replacement fuel filter, and new spark plugs that I will install later this week. (Maintenance items at 60,000 miles)

I’ll keep you posted.

Just wanted to update the post.



The replacement MAS fixed the check engine light. All is well now.

I have driven the car seveal thousand miles without a problem.

Hey for future refrence, check the key on, engine off voltage for the air mass

specs are around .980 - 1.030

Anything above 1.030 is junk.

Changing the air filters on a 112/113 (C-E-S-CLK-CL) at mileage over 50,000 will kill the air mass, especially if the air filters are original and have never been changed. Air mass has a hard time calculating the new, unstrained amout of air, kills it instanly.

Just a note. Glad you got it fixed. Also, if it has not already happened, At that mileage, I would prepare for a crankshaft sensor: symptoms: dies when warm, reststart after a period of time.

Will periodic (oil change intervals) vacuming of the air filters and box harm the air mass meter?

No, but air filters are recommend to be changed every 4 years or 60,000 miles, but periodic dusting should not hurt. But, I recommend to leave them alone and change according to recommendations, unless you put your CLK thourgh severe service.

Great information - especially about the check the key on, engine off voltage for the air mass specs are around .980 - 1.030 ... I'll definately file the information for future reference.

Thanks!