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I have an intermittent problem where the truck seemingly goes into limp mode but has only illuminated the CEL once. Shut down and restart clears the code. The code appears in my scanner either way, with or with our CEL and I can clear it from the scanner too.
My icarsoft scanner pulls it up as 123900 "The positive control deviation during boost pressure control is too high"
My inclination is that there must be some sensor or several sensors on the boost side of the intake that need a good spray with some electrical parts cleaner, or perhaps replacement, but I'm not sure where to start.
I did not check the part number, but yes the charge pressure sensor is located on the lower front right side near the throttle valve actuator-----you know that there are no cross reference faults between yours and XDOS and there are three sensors in the charge system, XDOS would tell me which one so the B5\1 charge pressure sensor is simply my guess!!
Thanks Plutoe! I ordered one of those to install on Saturday. Last question and thanks for your time. What are the other two sensors called and where are they located? I presume one is a temp sensor but just in case this doesn't work, I thought I'd ask.
Thanks, cheers.
Last edited by gaineserau; 07-05-2017 at 04:56 PM.
Reason: Spelling
Ok Plutoe and Dundee--I replaced the sensor in question and am currently out on a 2000 mile road trip. The code has popped up again (and the corresponding limp mode has occurred) twice in 1000 miles of driving. I will say that with the sensor replaced the throttle response is a little better than it used to be so I'm still happy I replaced it.
Any thoughts as to my next move? Temp sensor? Where are the other two sensors in the charge side of the system and what are the called? Would it be one of them or something else?
Hello again--anyone have any other suggestions for this? I am still getting this same intermittent code 123900. It only happens on road trips when I have driven it at least 100 miles or so on the highway. And even then, only now and then. Any advice??? I replaced the front right engine boost sensor.
Have you actually checked the boost pressure out of the turbo charger? and have you looked for any leaks in the charge air system. Meaning are ther any air leaks in the turbo boost system at the orings and seals. You might check that out.
I had a boost pressure code aswell a while back causing it to go in limp mode, it was the the rubber seal or gasket on the charge pipe i think? the seal somehow went missing
Ok Plutoe and Dundee--I replaced the sensor in question and am currently out on a 2000 mile road trip. The code has popped up again (and the corresponding limp mode has occurred) twice in 1000 miles of driving. I will say that with the sensor replaced the throttle response is a little better than it used to be so I'm still happy I replaced it.
Any thoughts as to my next move? Temp sensor? Where are the other two sensors in the charge side of the system and what are the called? Would it be one of them or something else?
Thanks again
Did you replace this component B5/1) and where did you buy it?
Did you replace this component B5/1) and where did you buy it?
You need to verify that you do or do not have boost before you go spending money on a sensor that may not be bad. If you remove the boost sensor and install a mechanical vacuum/boost gauge in the spot where the boost sensor was you can then run the vehicle to see if in fact you do have boost then you've got a failed sensor. I say this because i have done this procedure, but only after i replaced the sensor and that did not correct my issue. I still have an underboost condition and code 123900. Im still working on mine i have currently pulled the turbo to inspect the VGT mechanism inside the turbocharger. If the turbocharger isnt producing the boost then replacing the sensor is a waster of good $,,,,,,,, but do what you want?
Did you replace this component B5/1) and where did you buy it?
Dundee—actually it’s been a year since this post and I did buy a genuine Bosch replacement sensor, but I can’t remember where from. It was new in box. it has been replaced.
Two observations:
1.Why the problem goes away when you stop, turn off the car and turn it back on?
2.I drove with my scanner tool (Foxwell for MB) connected, when it goes on limp mode, I reset it while driving (no stop) and it the car immediately runs normal.
MB send me papers for a class action lawsuit related to Bluetec major problems, giving $3,500 plus some parts replacement, this is just a month ago.
Two observations:
1.Why the problem goes away when you stop, turn off the car and turn it back on?
2.I drove with my scanner tool (Foxwell for MB) connected, when it goes on limp mode, I reset it while driving (no stop) and it the car immediately runs normal.
MB send me papers for a class action lawsuit related to Bluetec major problems, giving $3,500 plus some parts replacement, this is just a month ago.
I did resolve the issue, however it was not a repair solution rather a long-term omission solution. I removed the computer shipped it to Canada 🇨🇦 and had that code and a number of other things deleted from it. My state doesn't require emissions or safety inspections. That was done 18 months ago. It has been approximately 30k miles since I did that and no check engine lights on increased fuel efficiency and it runs like a raped ape!!!
The reason that code kept coming up is that the computer programming does not allow for engine wear and turbo compressor wear to be compensated for. I ended up having a lazy turbocharger actuator Mercedes Benz wanted to throw a new turbocharger At it at the cost of $4500 I refused knowing there had to be another way I purchased an actuator from China and it was a piece of…..... I finally went to a turbocharger rebuilder in another city and they had an actuator that he gave me along with 2 other used ones off of Mercedes Benz GL 320 engines. Deleting the computer's ability to have the codes allowed my turbocharger actuator to be a little lazy yet still perform as it was designed when the mileage increases on the engine. I tow a 25' 4700 pound boat and a 28' 5800 pound camper with no problems through the mountains and on flat ground and still get 13 miles to the gallon with plenty of power. If Mercedes Benz and the US EPA government would have left things alone this engine never would have given me the trouble that has I will own another one and I will do the same deletes and some other performance improvements in the future I also failed to mention that oil consumption issue I had prior to this repair no longer exists It's amazing what happens when you eliminate an edr valve from a diesel engine that should be there in the 1st damn place.
Can you shoot me some more specifics about what exactly you had done in Canada. You sent the computer (ECU?) to a place in Canada that reprogrammed/deleted some things so you would no longer have this issue?
i too received something in the mail saying that by the end of this year I should receive a check from Mercedes for around $3,500.
i would like to figure this issue out. Sometimes it goes into limp mode 3 times in a day and other times I can go a week without any issues. I’ve replaced the turbo actuator, fixed some leaks, and spent hours in front of a computer trying to learn what is causing my problem.
if you could give me some more details on how you fixed your issues, I would really appreciate it.
Originally Posted by Rattlebox
I did resolve the issue, however it was not a repair solution rather a long-term omission solution. I removed the computer shipped it to Canada 🇨🇦 and had that code and a number of other things deleted from it. My state doesn't require emissions or safety inspections. That was done 18 months ago. It has been approximately 30k miles since I did that and no check engine lights on increased fuel efficiency and it runs like a raped ape!!!
The reason that code kept coming up is that the computer programming does not allow for engine wear and turbo compressor wear to be compensated for. I ended up having a lazy turbocharger actuator Mercedes Benz wanted to throw a new turbocharger At it at the cost of $4500 I refused knowing there had to be another way I purchased an actuator from China and it was a piece of…..... I finally went to a turbocharger rebuilder in another city and they had an actuator that he gave me along with 2 other used ones off of Mercedes Benz GL 320 engines. Deleting the computer's ability to have the codes allowed my turbocharger actuator to be a little lazy yet still perform as it was designed when the mileage increases on the engine. I tow a 25' 4700 pound boat and a 28' 5800 pound camper with no problems through the mountains and on flat ground and still get 13 miles to the gallon with plenty of power. If Mercedes Benz and the US EPA government would have left things alone this engine never would have given me the trouble that has I will own another one and I will do the same deletes and some other performance improvements in the future I also failed to mention that oil consumption issue I had prior to this repair no longer exists It's amazing what happens when you eliminate an edr valve from a diesel engine that should be there in the 1st damn place.
Dundee—actually it’s been a year since this post and I did buy a genuine Bosch replacement sensor, but I can’t remember where from. It was new in box. it has been replaced.
Did replacing boost sensor at the front of the engine solved the problem
Hello All, i searched the thread about the issues i have on my 2012 Mercedes E350 Bluetec that just recently started happening as driving it goes to limp mode and the codes i get are 123900 The boost Pressure is to low, and 16E100 the turbocharger1 boos pressure is to low, i have looked at some info on google and seen where people had issues with the module next to turbo that had to use sadder to connect the wires broken but on mine its not the case, i did a smoke test and don't really see any leaks, are there any suggestion what i can look
07-04-2017, 12:51 PM
