Check Engine issue- 2001 ML320 - Benzworld.org - Mercedes-Benz Discussion Forum

dss52487 · 12-18-2005, 08:41 PM

Folks,
After filling up fuel up to the half of the fuel tank, I started the engine and then "Check Engine" light came on. This is my second time to see the light. Previoulsly about 30 miles ago after previous gas refill, the light went on and then disappeared after couple of engine starts/stops.
The vehicle ran fine even with the light. Temperture was normal, the wheel balancing was stable and no shake in handling.

Possible causes:

1. I was told from someone that I may need to replace gas filter. Where is the gas filter located in? Is this something I can replace by myself? How much is it cost if I go to the dealership to replace this gas filter?

2. I was also told that I need to check the cap, twist it tight until it clicks 3 times. And also I may need tapping the fuel pump. If it is a pump sensor issue, I was told that it cost $500 mostly labor.

Have you ever tried this before and how did work?

3. I saw a comment that this may happen due to water in the gas refilled. Regarding water in gas you can add any dry gas made for fuel injections.but sometimes slight debris in gas can partially clog fuel injectors. Someone had that problem too his mb service manager recommends BK44 fuel additive to the fuel tank might help check out www.bgproducts.com.

Has anyone tried this and how did work?

AC_ML · 12-19-2005, 08:08 AM

First, you may want to fill your tank all the way full, and see if this happens again. If you fill it half way, the ML will need more time to pressurize the tank. More if the gas cap is not sealing correctly.

IF your vehicle is just working fine, you may want to change the gas cap first, before going to more expensive solutions. Be careful with MB dealers, they can take you to an unecessary several thousand dollar fix up solution if you are not careful.

You may want, too, to take your ML to autozone, or any other parts store, where they can read, using an OBDII, any DTC's (Diagnostic Trouble Codes) set on the computer. I wonder what is the computer's DTC error code and particular engine parameters set when the gas cap is loose.

On my wife's Honda, we need to replace the gas cap. Somehow, it needs to be tighten up every so often because it looses it's sealing properties. We took it to a local mechanic and he mentioned just to get a new gas cap from the dealer.

AC

Banker · 12-21-2005, 02:28 AM

First of all don't worry!!! :) sometimes it happens...
1 i think the main reason is a bad gas you've filled,.. try to refills in another place...

2 if you disconnect the battery for approximately 30 minutes then the lump must disappear...

3 another reason can be in old plug sparks, may be it's time to change them & clear the injection???...

dss52487 · 12-21-2005, 06:07 PM

Thanks much for your tips. Looking at the vehicle manual, I can read the DTC error code from the code reader that's located at the bottom of passenger seat near break pedal.

Do you know exactly where the DTC error code reader is located in ML?

Banker · 12-21-2005, 11:30 PM

Quote:

dss52487 - 12/22/2005 4:07 AM

Thanks much for your tips. Looking at the vehicle manual, I can read the DTC error code from the code reader that's located at the bottom of passenger seat near break pedal.

Do you know exactly where the DTC error code reader is located in ML?

This reader is located on the driver side!!! (not passenger) look again up from parking brake pedal.. (it looks like SCART input in TV(for example)).

dss52487 · 01-01-2006, 06:10 PM

I finally went to the local Benz service center to figure out what the problem is and how much it would cost to fix the problem. The mechanic says that it's Air Flow Sensor issue not reading correct level of air amount. Not replacing it would cause vehicle not moving forward as expected and abrupt engine stop while waiting for the signal at the intersection.

They sayd that the sensor should be replaced and costs about $840 including sensor part cost of $680, labor fee of $100 and tax.

Does this price (especially for sensor part cost) sound reasonable? Is there any place that I can buy this sensor in cheap and ship it to the local service center?

howard · 01-01-2006, 06:30 PM

It is pretty easy to diy. You can find them on e-bay. I just saw this one:
ebay item number 8026954559.

I have no info about the seller so the usual disclaimers apply.

Evangelist · 01-01-2006, 06:34 PM

Greetings! It's important to know that Mercedes requires that the engine be turned off PRIOR to beginning to fill up with gas. Filling up with the engine running will trigger a code and the Check Engine light. Also, it is extremely important that you tighten the gas cap AT LEAST 3 clicks, preferably more, like 5 or 6. It might be to your advantage to try this procedure before initiating any further repairs. Hope this helps.

God Bless!

Rick
http://www.EmbraceHisGrace.com

MB430VA · 01-01-2006, 07:22 PM

dss52487,

The Air Mass Sensor (AMS) costs around $250 online and seems very easy to replace ( aound 15 minutes ). Some people said that sometimes just cleaning the AMS would also do the trick. There are a few threads here about this subject. I had mine replaced at the dealer at around 600$. If I knew what i know now, I'd try to do it myself. Good luck.

Radomir · 01-01-2006, 08:51 PM

if it helps -- my dealer quoted me around 340 for hte part alone.. so 680 sounds unreasonably high, even for a dealer.. I bought it online for around 230 or so.. and it took approx 3 minutes to replace it (DIY)..