OBD 2 codes - PeachParts Mercedes-Benz Forum

sokoloff · #1 02-23-2008, 07:28 PM

My check engine light on the 210 came on today. Code reader showed two stored codes, P0100 for what I figure is the MAF and P0400 which shows up as EGR flow. Could the P0400 be stored in the system since May when I ran the car with the manifold off? I've had no check engine codes since then and I can't recall whether or not I used my code reader to read and/or erase any codes that might have shown up at the time. When I erased both codes today, only the P0100 one showed up again.

I cleaned my MAF the last time this happened about 14 months ago and all has been well until today. Tried cleaning it again today, but wasn't successful on my first attempt.

Anyone using the Pierburg MAF for the CDI's that's been mentioned on here before? The insert only runs about $85 or so.

TMAllison · #2 02-23-2008, 07:41 PM

Len - In my experience with a bad MAF it was VERY evident that a fault was occurring. There would be no turbo boost and it was difficult to get the RPM's over 3k.

If yours doesn't exhibit loss of power, I'd suggest checking the wiring and connections at the MAF. PO100 is a "circuit" malfunction. Its possible the ECU is simply noting a loss of communication occuring.

sokoloff · #3 02-23-2008, 08:32 PM

Terry - I don't recall there being much difference in performance last time the code came up or this time either, although today I only drove about four miles home after it came on. I do seem to think that I felt a little lurch when I think the light first came on. Maybe I'll get a chance tomorrow to air it out a little and see if the performance is down.

sokoloff · #4 02-25-2008, 05:22 PM

Took the car out for the first real drive since the check engine light came on. Light is still on, but it's hard to feel any difference in the car's performance. Still runs well, gets up to speed as before and no rpm limitations of any kind. As I mentioned in my last post, I don't recall there being much difference the last time either. I did buy the CRC MAF cleaner today and will give that a try and reset the codes. I did not reread the codes today. Will do that before I R&R the MAF sensor.

sokoloff · #5 02-27-2008, 03:05 PM

Tried the CRC MAF spray cleaner today. No luck so far shutting off the check engine light. Still showing P0100. It also shows 32.19 lb/min flow at the MAF. I'm not sure how that compares to what it is supposed to be. Anyone know? I'll drive it for a few days and see if the light goes off. I doubt it since the OBD II code reader wouldn't allow me to reset it. Then I'll spring for a new MAF. Again, there's virtually no difference in performance so far.

TMAllison · #6 02-27-2008, 03:17 PM

My generic OBDII scanner can delete that one. Surprised yours is giving you difficulty?

aklim · #7 04-16-2008, 03:04 PM

I replaced a broken MAF with the part and it works better. Not perfect but better. Sometimes it throws a P0100 code especially when I do WOT runs.

aklim · #8 05-20-2008, 11:47 PM

This is what I see. I borrowed an OEM unit and it works just fine. Switched to the "alternative" and once in a while we get the P0100 light. What that tells me is that if you are running a stock PCM, it probably will work. If not, probably not. I have a Speedtuning USA PCM in my car.