guyfromwinnipeg

Hey so my CEL came on. Used a cheap cellphone scanner that has always worked. And got code P0942 * indicator request*. Threw reserch it come up as two of the following:

* P0942- Hydraulic Pressure Unit.

*0942 (no p, a MB code) - the efficiency of the right catalyst is insufficient

I can't tell what one it could be for the following reasons.

The hydraulic issue is possible as when I had my transmission serviced the shop told me it was fairly dirty and could see it failing. As well as I get a code that does not trip my CEL that indicates my A sollonid is faulty.

The catylic converter is possible as my o2 sensor on that side failed for sometime before replacement and looked at the voltage of my 2nd o2 sensor and it does not flatline (indication that oxygen is flowing past the cat *faulty cat*)



Other discovered fault codes (possibly pending, current ormanufacturer specific)

P0746: Pressure Control Solenoid "A" Performance or Stuck Off

*P0750- Shift Solenoid "A"

*P2092- A Camshaft Position ActuatorControl Circuit Low bank2 b)

*P2096- Post Catalyst Fuel Trim System Too Lean bank1

My engine is running fine as well as my mpg

Any thoughts.

Azscott

I have pretty much the exact scenario occuring with my c230. Hoping you have done the hard work for me and can share your solution, or at least shed some light on the situation.

guyfromwinnipeg

What type of scanner are you using? I used a different (an advanced one) scanner and none of the codes came up other then the code that trips my CEL. For cat inefficiency. I tested my cat and it slightly failing.

So I can't tell what these other codes are from.

My guess is the cat code trips these other unrelated codes that are 'pending' and have not requested a cel.

I'll run a scan in the next two days and give you a update.

In the mean time use a better scanner or a shop scanner

Azscott

Im using a cheap bluetooth scanner i got on ebay. I was hoping its not the cat [obviously]. Im just concerned that the codes are suggesting a transmission issue. I bought this car a few months back so im trying to figure out someone elses problems that ive inherited. Got the car for a good price so i cant complain TOO much. But i appreciate your assistance.

guyfromwinnipeg

From my understanding some of the codes that come up on a regular scanner can seem like mb related codes. (Transmission vs engine codes )

The transmission uses a separate module as when I use my fancy scanner to check transmission codes I need to select a different module and no codes came up. Watch the YouTube videos on oxygen sensor diagnosis. It's a bit complacted at first but watch it again and you should understand.

Basically you should have no oxygen coming out of your tailpipe as your Cadillac converter uses the oxygen in a chemical process to get rid of harmful pollutants.

Azscott

Did you ever run those codes? Have you just given up and are driving with the cel on, or have you fixed the issue?

Adi-Benz

Maybe the sensors in the exhaust

Anuar2889

It was on the left bank earlier comes 3 days later both pop up. Need to emphasize that I’ve just change to a used ecu and this fault code popped up. Has been driving this monster for about 6 plus good years thou.

FRANC0

Hey guys I got same codes for an Eclass 2011 350MB
IF IT Helps I used AN INNOVA SDS430 SCAN TOOL pretty much accurate with many features to scan modules manually and get to the problem faster ...
i went and got me some carb/choke cleaner from Walmart (about$3.15) and a MAF sensor cleaner($6)
cleaned the throttle body with engine running and MAF SENSOR after that went under and took out the O2 sensors and sprayed them until I saw then clean installed them back connected battery back and started the car and NO MORE CODES..car ran very smooth after that. A little bit of cleaning maintenance was the problem for me