C63fora2w1

Ever since about a month after getting my car I have had random CEL lights come on and go off all by themselves. The light came on last Friday and was off again by Monday. I took it to my Mercedes dealer to let them trouble shoot it. The light was off when I dropped it off on Wed but these were the stored codes.

1351- Mass Air Flow Sensor 1 has a malfunction

374A- The internal data could not be stored in the control unit.

3741- Mass Air flow sensor 2 has a malfunction

3690- Component Left Hot Film Mass Air Flow sensor has a short to ground

Dealer checked all components, testing wiring, between both mass air sensors and ECU for resistance, short, or crossed wiring ALL CHECK OK. They could not find the cause of the error and released the car back to me and told me to come back if the light comes back on.

All of these codes have been logged in the last 700 miles since my 50k service. I asked them to check at that time and they saw the P0101 but it was not active at that time so they cleared all codes.

Ambystom01

Didn't you recently install a Eurocharged tune?

C63fora2w1

The above intermittent CEL predates the tune by about 4 months

Ambystom01

So you tuned a car that throws random CELs?

ZephyrAMG

Why is there so many facelift cars having electronic, transmission, cabin squeak, brake squeak, air leak issues? Pre FL all we have are headbolts....????

Hope all gets fixed...

mark1281

That is interesting. I have not had a single issue with my '13. It is only a few people compared to all who own one.

chrisridebike8

Any airbox mods? When i ran aFe filters and charcoal deletes on my stock US boxes I got some kind of MAF CEL. I don't remember the exact codes. Once I swapped to ROWs, the CELs went away. And I had a 374a once. I think I read that one doesn't really matter.

ZephyrAMG

Not you in particular. Look at the new posts reporting problems. Most are all facelift.

Not sure, but it seems with the:
1. Cooling issues
2. Cabin creaks
3. Brake squeals
4. Transmission jerks
5. Air leaks

...Something is not right

C63fora2w1

I have had none of those issues and 95% of the time my car has been perfect. I just get a random light that comes on from time to time and its always P0101. Clearly its something to do with the mass air sensors.

SuckaGDog

You didn't answer the question though. Do you have any air box mods including ROW?

Ambystom01

Have you tried cleaning the MAFs?

C63fora2w1

I have ROW boxes and AFE filters and left the row boxes on while it was at the dealer.

C63fora2w1

Yes and even swapped both maf's and still got the same light.

GatorMB

I bet the dealership flashed away the tune.

C63fora2w1

I did before I took it in..

mark1281

Yeah I have seen lots of the posts and threads made but it isn't that many people who have these. Granted there are way more factors involved than are accounted for. Even looking at all my service documentation, there isn't anything the dealer finds when they had my car in for service either. Maybe it's just luck....haha

C63fora2w1

The light was off when I took it in.. next time it comes on I'm going directly to the dealership..

Wiggis

These are the actual descriptions for the M156 - a bit more descriptive, which might help.

---

1351- Measured air mass from the right unreliable in comparison with the position of the throttle. (P0101)

374A- Failed to save the internal data in the control unit.

3741- Left thermoanemometric air flow sensor measures the mass of air is too large. / HFM signal duration period on the left is too high. (P010B)

3690- B2 / 6 (Hot-air mass flow meter on the left): open / short to ground or plus (P010C)

---

The only time I've seen P374A on my own car was when the battery was a bit low. Charged it for 24 hours on a battery conditioner and haven't seen it since. I think it's a tell-tale that battery voltage isn't where it needs to be, but nothing more than that.

Wondering out loud - check your Right air intake pipework for blockages that might cause the engine to pull too much air through the left, and not enough through the right...

mark1281

Not a bad idea.

jptaylor

quick question as i am not sure if they even exist, but are your aFe filters dry filters or are they oiled filters like K&N?

C63fora2w1

AFE are dry filters.

latinskllz

What Wiggis said about battery/voltage! How old is your battery?


I was having issues in my E60 M5 with the SMG throwing codes out of its ****. Slightest voltage drop would make it go into limp mode. Ended up purchasing a new AGM battery and all was well.

Given that the vehicle is a '13, it is worth checking battery if it's the original one.


Good luck man!

C63fora2w1

I believe that it is the factory battery but I have no way of knowning for sure.. Right now the car is running like a scaled ape. The light is very intermittent.. as in it can be fine for weeks then comes the light that may stick around for a few days and then go out on its own.

latinskllz

It would be worth getting the battery tested.


Mileage on vehicle?

NotABaller

Hope everything is ok with your car brother. May your drives be long and bills be short.