imsoGLad

My check engine light occasionally comes on and off. This has been happening for approx. a month. The vehicle is brand new(purchased in November) and has 2K miles.
Spoke with dealer over the phone and they suspect that it has something to do with gas cap not being tight but that is clearly not the case.
My local mechanic doesnt have the 2012 software to diagnose (check engine light) and the dealership is a three hour round trip.
So before making the trip, anybody experience something similiar???

alx

A loose gas cap on a diesel does not cause a cel. Diesels don't have an evaporation system so gas cap is not monitored.

Your truck needs to be read. A generic obd2 (like the one your mechanic has) can read most of the generic codes- there is nothing "2012" about that.

tjpdvm

Also have GL 350 2012, purchased November 24, and now has 4500 miles. The check engine light comes on two to three times a week, and stays on about a day. Will have checked at 10k service.

JHEM

The CEL on my GL450 illuminates when I drop below 1/4 tank of gas, and stays on until I fill up.

alx

that is not right.

it is possible that your fuel sender/ gage is implausable below 1/4 tank.

lkchris

Your car is under warranty and fixing a CEL problem is covered.

It will NOT be free anywhere besides a dealer.

Mbenz260e

Last 2 fill ups on my E350 BTC had something similar. I had under a quarter and filled up then got the CEL on right after which was gone the next morning. The next fill up the light came on before I filled up and I have a little over a quarter tank left (confirmed by amount of diesel it took).

According to the manual on page 267 the CEL can come on the diesel in the following condition:

Vehicles with a diesel engine: the fuel tank has been run dry
(Y page 164).
X Start the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency
running mode is canceled. The vehicle need not be checked.


The car definitely wasn't run dry as it didn't take near close to a full tank of diesel and the gauge didn't indicate reserve. The light resets it's self but it's weird. Didn't not any signs of being in "emergency running mode"?

Never had the problem in the '09 Ml320 BTC either?

imsoGLad

I will do the same, sounds like you may get to 10K before me. Let me know what the diagnosis is , please.

venchka

CEL coming on early in a vehicle's life is not limited to GL 350s. Our GLK 350 was delivered November 19, 2011. Last Sunday, at ~4,600 miles the CEL came on as were were leaving the house to drive 250 miles to Houston. The car ran fine all the way to Houston. I called Star Motors Monday afternoon and made an appointment for Tuesday afternoon. CEL stayed on until Tuesday afternoon when I started it to drive to the dealer. They checked the codes. Faulty intake manifold pressure sensor hose. Replaced.
Kudos to my wife for making me get it checked promptly. I realize that the CEL coming on is useless information by itself. However, it does indicate a problem somewhere. Waiting several thousand miles to get it checked out is risky at best.

Wayne

lester11590

I also took delivery of a new GL350 in January of this year, the check engine light went on/off 3 times so I took it to my dealer. I was told it was a known software problem and there would be a firmware update in Feb/Mar and I would have to bring the car in for a quick upload of the new computer software. I still have to call them and make this appointment. Interestingly enough, the light has not gone on since I brought the car in in late January. I will update once I have bring my car in again.

mschirmer

One other thing that can trigger the check engine light is if you're driving in wet weather and go through a deep puddle or standing water - if it splashes on the diesel catalyst, the rapid cooling causes the emission control system to spaz out triggering the CEL. The error will not necessarily reset automatically. Allegedly, there is a SW fix/download as part of a service campaign to fix this. Happened 3 times on my GL320 BT.

tjpdvm

Had my vehicle get its 10000 mile service. It gets picked up and returned so I did not speak with anyone, but this is what was on the invoice. "Inspect engine lamp DTC 20B11 stored in SCR module. Software issue. Necessary to backdate to level V22 as per conference call dated Dec-11." The light had slowed down to once every two weeks or so the last 2000 miles. Has run great for these first 10K. 24MPG carrying about 700lbs daily.

imsoGLad

My CEL has not come on for over 2 months. My situation does not fit into any criteria mentioned as far as triggering the CEL. I am still at only 6K miles and will have the dealer check into the software issue.

Thanks for the input everyone.

My GL 350 (2012) averages 18 city / 27 highway , although i have averaged around 30 MPG on some 50 mile trips which i managed to stay around 60 MPH.