For the past 3 days it's been a little cold in NY Long Island area, around 20-30s average. I get a P2279 code 2018 mercedes benz GLs 450 w/72k, last time any engine work done was in the summer 2021 changing plugs and filters so no recent moving around to say an air hose gets knocked off or similar however one thing I did was open and close the coolant reservoir cap to make sure it's closed properly, some air ecaped as expected but have done this many times on other cars and never had a CEL. It went away after 1 day of driving but returned after the car started this morning. Any ideas?

 

https://www.carobdcode.com/p2279-mer...ir-system-leak

Also have your fuel gas cap checked or replaced

 

thank you for the tip. I tighten the gas cap and cleared the code. if the light comes back on will update the thread

 

Code came back. I Saved a freeze frame on this scanner, anyone know how to download it?

never mind I found the SD card.

 

Check the intake box and plastic hose for cracks splits
also check intake air sensor that is flush and not sticking out or broken.

bank one should be the drivers side.

 

thanks again, I will recheck the hoses and sensors sometime today and report back. In the meanwhile here;s the freeze frame data at the time the code appeared. if there is anything on it that's off please let me know espcially MAP and fuel trim since I don't know what's normal.

One question the scanner mentioned BANK 1, is that on the right side (passenger) or left side (passenger)?

˜{"LB":"AutoScan->Engine[$07E8]->Read Codes->Pending Codes->Component Test->Freeze Frame",
"Lang":"en",
"VehicleName":"OBDII",
"Version":"1.1",
"JVer":"1.0"} ÷{"DATA":{"UT":"FF",
"VID":"0>VehicleInfo>Control Module>Diagnostic Menu>Freeze",
"TT":"Freeze Frame",
"WU":true,
"CS":-1,
"WR":[70,20,10],
"IS":[{"LB":"DTC that caused required freeze frame data storage",
"VA":"P2279","UNT":""},
{"LB":"Fuel system 1 status",
"VA":"CL",
"UNT":""},
================================================== ========
{"LB":"Fuel System 2 status",
"VA":"--",
"UNT":""},
================================================== ========
{"LB":"Calculated Load Value",
"VA":"31.0",
"UNT":"%"},
================================================== ========
{"LB":"Engine Coolant Temperature",
"VA":"69",
"UNT":"°C"},
================================================== ========
{"LB":"Short Term Fuel Trim -Bank 1",
"VA":"-2.3",
"UNT":"%"},
================================================== ========
{"LB":"Long Term Fuel Trim - Bank 1",
"VA":"-5.5",
"UNT":"%"},
================================================== ========
{"LB":"Short Term Fuel Trim -Bank 2",
"VA":"-4.7",
"UNT":"%"},
================================================== ========
{"LB":"Long Term Fuel Trim - Bank 2",
"VA":"-6.3",
"UNT":"%"},
================================================
{"LB":"Intake Manifold Absolute Pressure",
"VA":"38.0",
"UNT":"kPa"},
================================================
{"LB":"Engine RPM",
"VA":"625",
"UNT":"rpm"},
================================================
{"LB":"Vehicle Speed Sensor",
"VA":"0",
"UNT":"km/h"},
================================================
{"LB":"Ignition Timing Advance for #1 Cylinder",
"VA":"0.0",
"UNT":"°"},
================================================
{"LB":"Intake Air Temperature",
"VA":"6",
"UNT":"°C"},
================================================
{"LB":"Absolute Throttle Position",
"VA":"10.6",
"UNT":"%"},
================================================
{"LB":"Time Since Engine Start",
"VA":"713",
"UNT":"sec"},
================================================
{"LB":"Fuel Rail Pressure",
"VA":"11750",
"UNT":"kPa"},
================================================
{"LB":"Commanded Evaporative Purge",
"VA":"0.0",
"UNT":"%"},
================================================
{"LB":"Fuel Level Input",
"VA":"65.9",
"UNT":"%"},
================================================
{"LB":"Barometric Pressure",
"VA":"102",
"UNT":"kPa"},
================================================
{"LB":"Control module voltage",
"VA":"14.489",
"UNT":"V"},
================================================
{"LB":"Absolute Load Value",
"VA":"27.1",
"UNT":"%"},
================================================
{"LB":"Commanded Equivalence Ratio",
"VA":"0.999",
"UNT":""},
================================================
{"LB":"Relative Throttle Position",
"VA":"0.0",
"UNT":"%"},
================================================
{"LB":"Ambient air temperature",
"VA":"-6",
"UNT":"°C"},
================================================
{"LB":"Absolute Throttle Position B",
"VA":"10.6",
"UNT":"%"},
================================================
{"LB":"Accelerator Pedal Position D",
"VA":"6.3",
"UNT":"%"},
================================================
{"LB":"Accelerator Pedal Position E",
"VA":"5.9",
"UNT":"%"},
================================================
{"LB":"Commanded Throttle Actuator Control",
"VA":"0.0",
"UNT":"%"},
================================================
{"LB":"Type of fuel currently being utilized by the vehicle",
"VA":"GAS",
"UNT":""},
================================================== =================
{"LB":"Long Term Secondary O2 Sensor Fuel Trim - Bank1",
"VA":"0.0",
"UNT":"%"},
================================================== =================
{"LB":"Long Term Secondary O2 Sensor Fuel Trim - Bank2",
"VA":"0.0",
"UNT":"%"}]}}
================================================== =================

 

Can anyone identify this part?

Seems seems like a lot of air passing, if I rock it back and forth gently I hear the air suction change… still don’t know if that’s it. Help

 

That definitely could be your problem
Try getting replacement o rings
Looks to be air temperature sensor

 

Does any one have a repair manual showing how to remove the air intake plenum? Any tips? Computer has to be removed first then there are 4 bolts on each side of the plenum.
I have to remove the plenum in order to get to where that vaccum line goes under (Image 1). I sprayed trottlebody cleaner where that hose goes down the side of plenum and heard the changes in vaccum when the engine stalls so that's definately where the leak is. Image 2 shows a picture of the plenum removed showing what looks like where the line ends up.

 

resolved: the vent hose had a tear/crack and was replaced. Since the upper and lower intake had to be removed the gaskets were replaced in addition to the vent hose replaced with MB parts. All is well now, happy to report.

 

mike10872 - thanks for the follow ups - I also have an '18 GLS450 and have been following .... glad to hear you are back on the road. Steve

 

no problem, just don't know how that happened, cold weather related maybe. Here's a picture of the actual line that was replaced.

 

Glad to hear . Sucks that so much stuff has to come out for it to be replaced.

 

Mike10872,
I'm having the exact same issue with the vaccum line that you did. Can you please share the part number of that hose. I'm having trouble finding it. Also please a little instructions on how to get to it. Thank you so much Jorge

 

A2760182300-VENT LINE
A0239970345-O-RING

Since you have to remove the intake manifold, change upper and lower gaskets.

A276141078064
A2761410480

 

Thank you so much Mike. I dug into it and got it out after disconnecting many many britle cable connectors and wondering about the engine to find all the bolts. Not that bad actually just frustrating to keep breaking cable connectors. the part number in case others need it is A2760182300, exactly as you mentioned.
Thank you again to replying so quickly.

 

great glad to help, yes there were lots of brittle clips on the connectors.

 

Good info, Mike! I, too, have located the air leak under the intake manifold. Can you please tell me about how many hours you spent on the repair and are there any videos, documents, references you found to guide you through the repair?

Thanks in advance!

 

give yourself a good 2 hrs. I had to feel my way being careful not to break the plastic clips on the harness.

 

Yes about 2-3 hours is correct, as Mike mentioned those electrical connectors will break just be careful. I actually fixed mine by purchasing some vacuum line from the autopart store that fit perfectly over the old connections once the brittle plastic line that broke is removed. I feel that my fix is better than the original.

 

Hey Mike can you list the torque specs and directions to tighten the manifold bolts? Thanks

 

Hi Mike, Can you pls tell me what / how you got this resolved? P2279