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Scanned my 2015 GL450 after doing motor mounts a few days ago. Noticed I'm getting one fault code P06DA00. Code is current and can't be cleared. I did some research and it seems like this is common on a lot of MB engines. My understanding is it's a pattern failure and there is a wire that typically breaks internal to the engine in the oil pan. Is it correct this solenoid when activated reduces oil pressure in certain scenarios? IE. Engine is up to temperature and idling. The solenoid ACTIVATES to lower oil pressure and thus reduce parasitic drag/ fuel consumption. Is this correct? If so I'm gong to leave, it as this isn't worth the effort to repair and won't cause any mechanical issues down the road. Looks like its common enough Xentry calls for ignoring the error unless it's specifically called for in a test procedure.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Really don't know what to tell you. Have you gotten a quote on the repair or would you do it yourself? I’d only be concerned about excess pressure causing seals to be blown, but not sure that would happen.
Scanned my 2015 GL450 after doing motor mounts a few days ago. Noticed I'm getting one fault code P06DA00. Code is current and can't be cleared. I did some research and it seems like this is common on a lot of MB engines. My understanding is it's a pattern failure and there is a wire that typically breaks internal to the engine in the oil pan. Is it correct this solenoid when activated reduces oil pressure in certain scenarios? IE. Engine is up to temperature and idling. The solenoid ACTIVATES to lower oil pressure and thus reduce parasitic drag/ fuel consumption. Is this correct? If so I'm gong to leave, it as this isn't worth the effort to repair and won't cause any mechanical issues down the road. Looks like its common enough Xentry calls for ignoring the error unless it's specifically called for in a test procedure.
Please Enlighten Me O' Great Forum Members :-)
> CONGRATULATIONS:
You have the best failure you'll ever get ! Your engine is now graced with normal oil pressure for pistons cooling, lubricating camshafts journals and supplying VVT Phasers with working pressure.
The bad thing to do would be to repair that failed solenoid without realizing the benefits.
When solenoid harness fails, the oil pump produces only normal pressure output instead of reduced idling low pressure.
> CANCELED CHAOS = ENGINE BLESSING!
As it is without solenoid control, your engine has excellent low rpm torque with smooth VVT controls, the quiet HPFP roller is well lubricated and the camshafts are normally oiled to reduce friction.
Piston are cooled by working squirters so fresh oil is no longer being vaporized black under 500Miles.
Intake plenum is no longer filled up with quarts of PCV oil that coat intake valves - I think all that canceled chaos is a blessing!
I was not directly lucky until I unplugged my stupid solenoid to discover these benefits. I colaborated with a brilliant scuba diving friend who's expert in large marine engines and top notch yatch maintenance. As he loves racing his twin-turbo, he research performance in-depth.
The oil pump controls are abused by software nerds. Low pressure at 750RPM idle, sure why not B U T Bosch ECU toggles low pump pressure up to 3,500.RPM THAT'S RECKLESS engine management.
Driving at highway speed with limited oil circulation becomes obviously ridiculous as soon as you try the normal pressure with solenoid unplugged.
The engine becomes alive with normal lubrication.
> PUMP OUTPUT: low vs Normal
- Solenoid would be useful if pump output was greater or to regulate pressure to a stable 40PSI - NOPE NOT HERE!
- We have a nomal output pump that has a low pressure setting controlled by a On/Off solenoid (PWM is used at 10% to check circuit activity).
> NO SENSOR... no regulation!
-- Can you believe M276 does not have a $2 oil pressure sensor to measure available oil pressure?
-- So clearly ECU is not able to regulate pump by pulsing solenoid to deliver target pressure.
-- The fancy $2 opportunity here would have been to regulate smooth oil pressure regardless of RPM. Pump pressure varies normally with RPM. Low pressure is a side-effect of low RPM not something beneficial.
> MOAB... (Mother Of All Bugs!) :
It's an ECU bug to limit oil distribution all the way up to 3500.RPM. Low oil pressure should be limited to idle only.
There is a long list of low oil side effects:
weak engine driveability
cracked pistons crowns
scored cylinders walls
piston rings jamed by burned oil carbon
wasted VVT phaser lock pins
flatened camshaft rollers
worned out soft cam lobes
scored HPFP piston jams
toasted CPS leak "oil-in-harness" $$$$$
crankcase blow-by, burned seal leaks
oil burned black under 500 Miles
quarts of oil vaporized into plenum
contaminated Lambda and catalytics
environmental SMOG air particles
endless service opportunities
chaos not exactly unmanaged...
> DRIVEABILITY SHINES!:
- Engine is effortlessly smooth from 0 to 70+ . Low speeds and high speeds are really transformed.
- Pedal is now super touchy responsive without LAG or hesitations (poor Trim and VVT positioning!)
- Easily too fast versus pushy and heavy.
> SO FAR... I PULLED THE PLUG!
- I dont know what kind of plastics Mercedes uses to limit the life of these oil pumps. As OP noted, solenoids sure fail all right. 👏
- Perhaps normal pressure is not good for these modern oil pumps - Who knows ?
- They run off a separate crankshaft chain with a tensioner. Nothing too special besides dual-rate variable chamber...
- These pumps are not "high+normal" pressure, only "normal+low" pressure. Opportunity for cheaper build.
You know mileage may vary... "proceed at your own risks with experimental research." - Knowledge courtesy of @S-Prihadi mbworld members such as tuner Master Tasos Moschatos.
Last edited by CaliBenzDriver; 10-30-2023 at 06:47 PM.
Reason: - Let there be Light-
Yea, that is pretty much what I figured. I think I ran across a post where you were digging to this exact same thing. Not sure how long it's been this way since we have only owned the vehicle about 6 months. I wonder if Mercedes adjusted the original ECU programing so this doesn't trip the MIL and trigger a bunch of warranty work even though it's better for the motor. Sneaky *******s ;-)
Really don't know what to tell you. Have you gotten a quote on the repair or would you do it yourself? I’d only be concerned about excess pressure causing seals to be blown, but not sure that would happen.
I typically do all work myself... But based on what others are saying it's best to have it disabled anyway.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
So, is the cable that attaches the solenoid to the cable harness completely enclosed within the oil pan, or can it be easily disconnected without opening the pan?
I typically do all work myself... But based on what others are saying it's best to have it disabled anyway.
Many cars have electronic and electricals working in hot ATF fluid... it's almost as if this harness fails to preserve engine after enough standard damage is done.
> KILLER INCENTIVE:
These amazing solenoids do not always fail with blessings - Sometimes owners get handed a short straw!!
Stuck solenoid plunger causes pump stuck on low pressure only.
Currently when engine temperature, engine load or RPM are exceeded the ECU disables the solenoid to momentarily allow normal oil pressure. It then powers the solenoid backup to resume low pressure - What that means is the solenoid does cycle onceva while. What this does is allow chunkies to move around and particles to accumulate.
Eventually plastic valve jams and causes pump to be stuck on low oil output: "game over!"- This causes catastrophic engine destruction.... blue crankshaft and rods
> Current control logic:
pump normal pressure requires no solenoid actuation.
pump low pressure requires active solenoid.
Junko solenoid plunger can jam and cause killer stuck on low oil only.
The way I see this is... having the solenoid unplugged is pure benefits. ✌️
> Grey Matters... Open vs. Closed:
-- Less metal friction wear and less burned oil carbon is less likely to jam solenoid plunger with contaminents.
-- I don't believe oil is circulating through solenoid when it is deactivated.
-- Perhaps activating solenoid shuts the plunger to interrupt control flow
--- Unplugged and zip-tied is my solenoid status.
++++ ENHANCEMENTS for great people around here...
How to prevent high RPM during low pressure event:
additional oil sensor trigger a limp-mode protection or disables ignition.
Reprogramming valve to only be active at idle would be nice enhancement but killer valve plunger can still jam.
Access to solenoid body for inspection is an oil pan surgery. Not on regular basis then.
"No solenoid valve means less additional failures."
Last edited by CaliBenzDriver; 10-30-2023 at 06:50 PM.
Reason: nothing's simple
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
So, you need to remove the oil pan to disconnect the solenoid? I was hoping it could be disconnected where the plug connects to the engine block. In the attached photo, the guy talking said the gray end (round connector) "attaches to the engine block." I've got to believe it attaches to the cable harness that connects to the ECU. It would be cool if you could disconnect it without opening the oil pan.
Yes, you can disconnect the engine harness right next to left side of crank pulley ... then zip tie it so it does not rub around the moving parts (belt, pulley).
In my shortcut, the internal oil pan harness and solenoid stay as is: done!
However if you want to repair OP's fault that is what you need replaced. I think the harness itself is what fails before electric solenoid valve puts out tricks: mechanical jam and electrical coil ...
+++++ 30mph test drive:
Go drive like 10 Miles around town traffic and notice the torque from 1000.RPM then hear how metallic sounds from camshaft and HPFP are smoother.
This helps the ECU/TCU quickly learn new base performance for mixture and shift points.
Once you are statisfied go open up the horses
Last edited by CaliBenzDriver; 10-30-2023 at 10:15 PM.
Anyway to verify valve position as a sanity check?
Should be fine but you know what they say about people that assume
Looks like no feedback loop.
If your solenoid plunger was stuck on low pressure mode, your car would be long parked at a junkyard
During engine startup the ECU triggers normal pressure to help refill the hydraulic tensioners and drained VVT gears.
There's no control thus no code when the pump fails to switch to normal pressure - With a pressure sensor ECU could limp-mode safely to prevent catastrophic damages. Circling the drain with limited lubrication is not my cup of tea... "The Best Or Something".
A few engines (AMG?) are sayed to have pressure sensors.
> Missed Opportunity:
When ECU switches oil pump to normal pressure, the VVT phasers solenoids must react. This sudden oil pressure surge messes up camshaft timings, that impacts combustion.
Having a smoothly regulated oil pressure with closed loop feedback sensor and PWM control would be awesome.
No1 Denso is likely doing it while Bosch champions its basic design.
Thankfully we have options to cancel this chaos.
++++ starter spins faster:
this afternoon I was running errands with my wife and noticed something I was not used to: the starter really launching the engine when it starts.
Before the starter would crank and as soon as the HPFP built up enough pressure it would start running.
Now starter easily spins the engine faster... I attribute that directly to better lubrification. The passenger side lobes that drive the HPFP roler are more quiet.
✌️
++++ Not ALL ...
The current oil pressure Mgt to drive Hwy on limited lube clearly does not blow up all engines right away, cracked pistons excepted! Certified Oil Grade may be essential to tolerate new extremes.
The flip side is when we buy a luxury priced vehicle it's not to struggle with hand-made chaos.
Last edited by CaliBenzDriver; 11-01-2023 at 12:34 AM.
Reason: starter launches engine
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by CaliBenzDriver
Yes, you can disconnect the engine harness right next to left side of crank pulley ... then zip tie it so it does not rub around the moving parts (belt, pulley).
I need to get under the car. I could not see the wiring harness from above.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
I was surprised to hear (or realize) that the solenoid holds low pressure until 3500 rpm. I am usually under 2000 rpm in normal driving and don't come close to 3500 rpm unless I'm flooring it.
Great post and technical input on the issue. The consensus is to disconnect that connector behind the crank pulley? No check engine light - just a pending fault? And the result is full oil pressure at all RPMs?
I was surprised to hear (or realize) that the solenoid holds low pressure until 3500 rpm. I am usually under 2000 rpm in normal driving and don't come close to 3500 rpm unless I'm flooring it.
Now you understand why your engine is kinda jerky and not smooth below 2000.Rpm... the VVT has a hard time working with low pressure to dial camshaft timings.
> Dry HPFP bangs VVT locks... :
When you hear the smooth quietness of well lubricated heads, more things begin to make sense....
You know how Bank-1 intake VVT gear is the first to rattle, right?
I wouldn't be surprised if the passenger intake camshaft had a real hard time driving the dry roller + piston of the HPFP.
So the lock pin rattling announces tougher news about HPFP going South.
The oil distribution path make HPFP rear location the very last served oil outlet thus the most starved with any remaining pressure. This is only additional stress on VVT, we know it doesn't happen overnight.
> Re-Adaptation Time:
Based on my recent experience, the engine learns the new VVT control and improved mixture control in about 500Miles then another 500Miles on top of that for tranny to use the low torque shifts.
Engine sounds better right from the beginning and runs great after 1,000.Mi self-adaptations.
Last edited by CaliBenzDriver; 11-03-2023 at 03:36 PM.
Reason: Good Gets Better
I chickened out. Disconnected the connector which is not too difficult. But I reconnected it as it seems risky to mess with oil pressure system as designed. This is definitely possible to do and the gained oil pressure at low rpm doesn’t overload the oil pump?
vehicle is 2018 GLC with 274. But also have 2016 E350 with 276. Just got the GLC and oil change was done by a Volvo dealership so I was pretty sure not the right oil or filter. Sure enough … STP branded China oil filter and who knows what oil. Used Mann filter and Mobil 1 5w-40 SP rated. Difference in engine noise alone is a huge improvement. Luckily only about 200 miles on the wrong stuff.
I chickened out. Disconnected the connector which is not too difficult. But I reconnected it as it seems risky to mess with oil pressure system as designed. This is definitely possible to do and the gained oil pressure at low rpm doesn’t overload the oil pump?
vehicle is 2018 GLC with 274. But also have 2016 E350 with 276. Just got the GLC and oil change was done by a Volvo dealership so I was pretty sure not the right oil or filter. Sure enough … STP branded China oil filter and who knows what oil. Used Mann filter and Mobil 1 5w-40 SP rated. Difference in engine noise alone is a huge improvement. Luckily only about 200 miles on the wrong stuff.
Great you noticed the service was not done to specifications. Unfortunately, once again if you want it done correctly, you have to do it yourself.
If I had to pick which of the two vehicles requires immediate attention and monitoring, the GLC with the M274 engine is the winner. The M276 has its issues, but compared to the M274 it can be considered a perfect engine.
Regarding your concern about messing around with the engine design, here is the link to MB own words about this solenoid,
I think the main impacts linked to the abuse of the pump solenoid are four folds:
- impact the 20psi piston squirters
- impact the VVT timing gears
- impacts engine performance
- impacts vehicle longevity
It may be nearly inconsequential to run idle engine on low lubrication.... near idle is low energy.
Runing a speeding engine with marginal oil pressure is a delicate act to balance heat production and premature wear of friction surfaces.
The OEM considers intermediate speeds as a high-idle and this works. Many engines are still ticking to prove it. When the special piston coating wears out, it splits then the journey stops.
Speaking of valves....
This little valve reminds me of the Schrader TPMS. It's a super advanced system with an Achilles heel. As soon as the undersized steel core has a chance to rust, troubles unfold.
Dealers can only side with the business they thrive on. MB designs products for calculated reasons. What we do with our property is based on personal judgements.
I don't know what undersized engine plastic is being stressed by normal engine lubrication if any. Going outside the envelope always offers risks and sometimes rewards.
My choice was sort of easy. I was underwhelmed by the smell of vaporized old-engine oil in my new Mercedes.
Limited cooling :
Oil cools the hot friction parts. When a lot of heat is sensed or a lot of gasoline is being injected or calculated engine load calls for it, the Bosch ECU allows normal oil cooling.
I don't know any positive aspects of limited oiling business besides lawyers putting Mercedes in the news - Perhaps a well managed American class action is cheaper than the cost of a marketing campaigns?
+++ Concealed root cause... very limited scope:
Let me read the "class-action" to see how this is framed...
Limiting this poor lube struggle to M274 without including M276/8 is serious mistake neglect.
Don't forget Japanese brands (HMS, TMC, Denso,...) are licensing designs from mothership.
I know Toyota and GM have limited oil chaos as well, it's not only a few Mercedes 4Cyl... this is a serious setup
-- The litigation filing points at balance shaft issue causing engine vibrations - That's ridiculously amazing.
-- Sometimes pistons may be involved as well. Piston lubrication default is not remotely involved... No root cause is researched.
-- It's just basic bad luck... A few people need engine repairs... business as usual... its randomly normal: "Bell curve distribution".
-- No teeth, nothing.
++++ Double standards...
Mercedes occupies a very peaceful spot in the litigation arena compared to others. 👏
Mercedes is working on it, no worries. "Mercedes has been known for its luxurious vehicles and outstanding customer service for years."
-- Wonder who had a hand writing these filings?
>> Hyundai sold cars with defective oil pumps and failed to disclose it.
"Hyundai knowingly concealed and failed to disclose this oil pump defect to its customers."
"negligence, unjust enrichment, fraud by omission, negligent design defect, breach of implied warranty of merchantability..."
-- Therefore they must get milked a little.
>> Honda Motors recalls millions of cars due to camera glitches.
Litigators spared no expense to find the root cause: "The root cause behind the extensive failures (...) has been identified as the improper design of the Communication Coaxial Cable - Thus, necessitating an immediate recall."
"Due to the faulty design, the coaxial cable could not maintain the proper signal transmission.
The substandard production process led to the disruption of signal connections ... resulted in flickering camera failure."
-- OMG the $20 camera is bad! Totally unacceptable.
Imagine if a few result oriented engineers worked on MB chaos: battery/YoYo, CANBus faults and solderless modules, low oil pressure ....
Last edited by CaliBenzDriver; 11-06-2023 at 05:07 PM.
Reason: 3+1 makes 4
Wow - thanks @juanmor40 and @CaliBenzDriver for taking your time to provide such detail. I'll (re)do this tonight. Thanks again, much appreciated.
You may end up being the last owner driving M274 and the dealer wondering why your engine is so strong?
We want to know your impressions as you go along your first 1000Miles - What do you notice with engine response, idle sounds, crank starting speed, 900.RPM torque, driveability City/Hwy.
10-30-2023, 01:44 AM
Looks like no feedback loop.
