2010 MB GL 450 Lowpower lean DTC

Bernie Diagnostician New Mexico Posted   Latest  
Case Study
ATS - Automotive Test Solutions
Driveability
P0171 — System Too Lean Bank 1
P0174 — System Too Lean Bank 2
Low Power
Intermittent Misfire

Here is a case study i have just completed. This MB GL 450 has had a lot of parts installed but still runs lean, I hope this helps.

diag​.​net/file/fo91nkbef…

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Glenn Owner/Technician
Texas
Glenn
 

Thanks Bernie, This is another example of how engineers are complicating vehicles more all the time. This is right up there with a tech replacing only the pressure pump, but not replacing the pickup sock just to save $15.00. Maybe the shop that replaced the pump did not know any better, but maybe they did? Designs are changing and repair data is becoming questionable. I wonder if the repair…

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Frank Service Manager
Nevada
Frank
 

Welcome to my world! Great video, thank you

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Caleb Diagnostician
Indiana
Caleb
 

Thanks Bernie, great stuff.

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Bob Technician
Massachusetts
Bob
 

Using the pump current and rpm to find a restriction is a great technique. It's too bad many components are so hard to get too. That's one of my biggest frustrations in diagnosing, getting to the necessary test locations. Bernie is spot on here, very often that's the longest part of the diag.

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Eric Owner/Technician
Massachusetts
Eric
 

Change intake gaskets, smoke test wont show.

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Ray Diagnostician
Ontario
Ray
 

Thanks Bernie, good work!

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Marty Technician
California
Marty
 

Thanks for the great demo, appreciate the clarification on using the “power” option in the “sharpshoorter” mode. Always learn something from you sharing your knowledge and diagnostic strategies. Much appreciation. P.S. Yes, the engineer that designed the access to the fuel pump/and filter on M and G class Mercedes should have been fired!

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Tad Owner/Technician
Florida
Tad
 

Long time, no see, Bernie… Been watching your vids and drooling over your scope/scanner system for what is, now, something like 17 years… “Mercedes Benz - The most over-engineered car in the world”

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Rudy Technician
Utah
Rudy
 

Bernie- a few questions. Just to clarify,it is ok to use your transducer for fuel pressure testing? No damage will occur? When testing the pressure, I assume you will still get small dips in the pressure reading due to injector opening,correct? If an injector was plugged, would that show in the pressure waveform?

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Bernie Diagnostician
New Mexico
Bernie
 

Rudy It is ok to use these pressure transducers wet or dry. Yes there will be a small pressure drop in the waveform, be careful when looking at pressure drop to indicate if the injector opened or not hydrodynamics is very hard to figure out.

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Rudy Technician
Utah
Rudy
 

Thanks.

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