GL350 - Periodic poor acceleration - am I in going into "limp mode?"
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 350
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From: Palo Alto, CA
2011 GL 350, P1 Package, HID headlamps, Blind spot assist, Parktronic, Wood steering wheel
GL350 - Periodic poor acceleration - am I in going into "limp mode?"
Over the last couple of weeks, my 2011 GL 350 just has no get up and go at the first start of the day. It's not particularly cold here in California, but I've only seen this happening when the truck has been sitting for a while - and it's not every time.
When the problem is going on, I can floor the accelerator and I get barely perceptible acceleration. Think 0-60 in one minute. If I pull over and turn off and restart the motor, things are normal again and I have the usual power and torque.
There are no codes, no check engine light.
Is this the famous GL "Limp mode" - Anyone seen anything similar or have any ideas?
When the problem is going on, I can floor the accelerator and I get barely perceptible acceleration. Think 0-60 in one minute. If I pull over and turn off and restart the motor, things are normal again and I have the usual power and torque.
There are no codes, no check engine light.
Is this the famous GL "Limp mode" - Anyone seen anything similar or have any ideas?
Thread Starter
Senior Member
Joined: Feb 2011
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From: Palo Alto, CA
2011 GL 350, P1 Package, HID headlamps, Blind spot assist, Parktronic, Wood steering wheel
I wrote that last post from the airplane coming home from JFK - kind of cool. Anyway the truck started with the same problem when I got off the plane, so I drove by the dealer and asked them to look at it.
They said the fuel system / injectors were reading funny - but it was 4:30 and they didn't have time to finish diagnosing and I need the truck tomorrow to get our Airstream out to the upcoming Stanford vs. Utah tailgater this weekend.
So I'll suggest EGR to them and let you guys know what it was if/when they figure it out.
They said the fuel system / injectors were reading funny - but it was 4:30 and they didn't have time to finish diagnosing and I need the truck tomorrow to get our Airstream out to the upcoming Stanford vs. Utah tailgater this weekend.
So I'll suggest EGR to them and let you guys know what it was if/when they figure it out.
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
No it does not.
It can be any of the many things that put the ECU in to limp mode.
I still have trouble believing that the engineers who wrote the code put in lots of safety traps and did not have them write errors to memory.
Last edited by N_Jay; Nov 13, 2014 at 10:17 AM.
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Yes, I know, mine has done the same thing (as have many others here).
When I said "I can't believe" I didn't mean that I did not believe it could happen, but rather, I meant "What kind of f-ing software architect would design a system with routines to catch error conditions that put the controller into a "safety mode" and not add in a routine to capture the event.
It has been blamed on EGR, MAF, Temperature sensors, DPF filter pressure sensors, Tumbler Flap motors, and a host of other potential issues.
Right now I am betting DPF pressure sensor. Mine does it in cold and wet weather.
Thread Starter
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Joined: Feb 2011
Posts: 350
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From: Palo Alto, CA
2011 GL 350, P1 Package, HID headlamps, Blind spot assist, Parktronic, Wood steering wheel
It is not throwing any codes.
I'm going to leave it at the dealer this coming Tuesday for further diagnosis for a couple of days while I am away at a business trip.
When they plugged it into their computer the other night when it was exhibiting the problem, they said that part of the datastream related to the fuel supply / fuel injector system "looked funny."
And yes - it seems super silly that if the engine control unit knows enough to put the motor in limp mode, for sure it should spit out sufficient data to let a technician know what it thinks the problem is.
I'm going to leave it at the dealer this coming Tuesday for further diagnosis for a couple of days while I am away at a business trip.
When they plugged it into their computer the other night when it was exhibiting the problem, they said that part of the datastream related to the fuel supply / fuel injector system "looked funny."
And yes - it seems super silly that if the engine control unit knows enough to put the motor in limp mode, for sure it should spit out sufficient data to let a technician know what it thinks the problem is.
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Out Of Control!!
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Good luck with the dealer. At last yours seems to be happening consistently enough to know when it is fixed.
Mine is 3 to 5 times a winter. Enough to be annoying but too few to start throwing parts at it or to get it to the dealer "limping".
I am thinking about trying the DPF pressure sensor, because it is under the car when it gets wet (part of my symptom) and is a part others have had good luck fixing the issue.
Mine is 3 to 5 times a winter. Enough to be annoying but too few to start throwing parts at it or to get it to the dealer "limping".
I am thinking about trying the DPF pressure sensor, because it is under the car when it gets wet (part of my symptom) and is a part others have had good luck fixing the issue.
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From: middle o' ma
15 AMG S63 4-matic coupe
I'll take a shot that it's a throttle position sensor.
My wife's S430 had this issue.
I was driving along and suddenly it lost all oomph but didn't stall.
We were able to get it to the dealer, again no codes or check engine light.
Shut it off, went in did paper work and came back out with mechanic for a ride, and it ran fine.
Sure enough the high side resistor network was faulted.
My wife's S430 had this issue.
I was driving along and suddenly it lost all oomph but didn't stall.
We were able to get it to the dealer, again no codes or check engine light.
Shut it off, went in did paper work and came back out with mechanic for a ride, and it ran fine.
Sure enough the high side resistor network was faulted.
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Joined: Oct 2012
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From: California
2010 GL350, 2005 BMW X5 4.8is, 2015 BMW 328d
Is the limp mode accelerating up a hill? or on surface streets? What does the dash say? Check engine light? If you get no response from the turbo, then check the fuel delivery, i.e. fuel filter, pump, pickup, sender,etc. Best thing to do is to OBDII query, get a diagnostic. Autozone does it for free. BTW diesel engines don't have a throttle.
Last edited by drgeeforce; Jan 31, 2015 at 03:59 PM.
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Is the limp mode accelerating up a hill? or on surface streets? What does the dash say? Check engine light? If you get no response from the turbo, then check the fuel delivery, i.e. fuel filter, pump, pickup, sender,etc. Best thing to do is to OBDII query, get a diagnostic. Autozone does it for free. BTW diesel engines don't have a throttle.
Limp mode is reduced power (guessing no, or very limited boost)
May also be a limit in upper RPM.
Hills are only noticed due to needing more power.
Dash says nothing out of the ordinary.
No Check Engine
No dash display errors or events.
I doubt it is a fuel issue as it is sudden onset and completely gone on restart.
Was not able to do ODB test since restart clears issue.
No stored ODB errors from a simple tester.
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From: California
2010 GL350, 2005 BMW X5 4.8is, 2015 BMW 328d
Boost is what happens when the turbine spins fast enough to charge the incoming mixture. The lack of boost at highway speeds means the turbine is not turning fast enough to create boost or something is bleeding off the pressure, i.e. wastegate/blow-off valve. The first condition would be created by shifting into neutral at highway speeds where coasting would not produce exhaust gases to drive the turbo. Second is the electronic fuel management is opening the wastegate/blow-off valve decreasing the boost. Common places to look for would be a vacuum leak.
Out Of Control!!
Joined: Aug 2010
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Boost is what happens when the turbine spins fast enough to charge the incoming mixture. The lack of boost at highway speeds means the turbine is not turning fast enough to create boost or something is bleeding off the pressure, i.e. wastegate/blow-off valve. The first condition would be created by shifting into neutral at highway speeds where coasting would not produce exhaust gases to drive the turbo. Second is the electronic fuel management is opening the wastegate/blow-off valve decreasing the boost. Common places to look for would be a vacuum leak.
As such the ECU can greatly reduce or possible eliminate the boost when desired to limit engine power production.
Possibly the limp mode is enforced simply through the limitation of fuel. Anyone KNOW for sure??
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From: California
2010 GL350, 2005 BMW X5 4.8is, 2015 BMW 328d
You sir are correct, the ECU controls both the pre and post pressures in the turbo, but a fault in the ECU would trigger a CEL. Fuel starvation as you propose would be felt across the power band, not just at highway speeds.
The Sprinter utilizes a Garrett VVT with vacuum actuator. Loss in vacuum disables the vanes. That will not trigger a CEL.
http://www.mercedes.gen.in/WP35/merc...fault-finding/
Although the most common CEL seen with a turbodiesel with no power is a P0299 Under Boost condition. Default is vanes open.
A few I have fixed with just a spray of WD-40 on the linkage-solenoid transition. Most I have fixed by replacing the vacuum hose to the turbo. Temperatures near the turbo are brutal, hence the aluminum shield.
The Sprinter utilizes a Garrett VVT with vacuum actuator. Loss in vacuum disables the vanes. That will not trigger a CEL.
http://www.mercedes.gen.in/WP35/merc...fault-finding/
Although the most common CEL seen with a turbodiesel with no power is a P0299 Under Boost condition. Default is vanes open.
A few I have fixed with just a spray of WD-40 on the linkage-solenoid transition. Most I have fixed by replacing the vacuum hose to the turbo. Temperatures near the turbo are brutal, hence the aluminum shield.
Last edited by drgeeforce; Feb 3, 2015 at 05:50 PM.
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
You sir are correct, the ECU controls both the pre and post pressures in the turbo, but a fault in the ECU would trigger a CEL. Fuel starvation as you propose would be felt across the power band, not just at highway speeds.
The Sprinter utilizes a Garrett VVT with vacuum actuator. Loss in vacuum disables the vanes. That will not trigger a CEL.
http://www.mercedes.gen.in/WP35/merc...fault-finding/
Although the most common CEL seen with a turbodiesel with no power is a P0299 Under Boost condition. Default is vanes open.
A few I have fixed with just a spray of WD-40 on the linkage-solenoid transition. Most I have fixed by replacing the vacuum hose to the turbo. Temperatures near the turbo are brutal, hence the aluminum shield.
The Sprinter utilizes a Garrett VVT with vacuum actuator. Loss in vacuum disables the vanes. That will not trigger a CEL.
http://www.mercedes.gen.in/WP35/merc...fault-finding/
Although the most common CEL seen with a turbodiesel with no power is a P0299 Under Boost condition. Default is vanes open.
A few I have fixed with just a spray of WD-40 on the linkage-solenoid transition. Most I have fixed by replacing the vacuum hose to the turbo. Temperatures near the turbo are brutal, hence the aluminum shield.
These events are too consistent to be a bug, so I believe it is the intentional activation of specific engine map.
What disappoints me is not storing the code to be easily read upon service.
Member
Joined: Oct 2012
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From: California
2010 GL350, 2005 BMW X5 4.8is, 2015 BMW 328d
Have you corrected your "limp mode" problem? My guess if there's no code being given, then you may have carbon buildup. Once a month or bi-weekly mashing the accelerator pedal to rid the EGR and Turbo of these deposits will help maintain performance. Additives are useless compared to a turbo strip down and carbon cleanup.
Out Of Control!!
Joined: Aug 2010
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Have you corrected your "limp mode" problem? My guess if there's no code being given, then you may have carbon buildup. Once a month or bi-weekly mashing the accelerator pedal to rid the EGR and Turbo of these deposits will help maintain performance. Additives are useless compared to a turbo strip down and carbon cleanup.
Why do you think it is carbon?
It has never happened in warm or dray weather.
There is a lot of guessing on this issue, but (again) the most common successful fix has been the DPF differential pressure sensor. (Under the car where it and its electrical connector get cold and wet)
Newbie
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2010 gl350
my 2010 gl 350 is doing the same...i can floor it and it barely gets past 2 in the rpm gauge...i have to use the paddle shifters to change gears while accelerating otherwise it gets stuck before going up to the next geat...also notice it when slowing down...pedall to the floor and no power like before...did anybody figure out what the problems was
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
my 2010 gl 350 is doing the same...i can floor it and it barely gets past 2 in the rpm gauge...i have to use the paddle shifters to change gears while accelerating otherwise it gets stuck before going up to the next geat...also notice it when slowing down...pedall to the floor and no power like before...did anybody figure out what the problems was
Newbie
Joined: Oct 2014
Posts: 6
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GL350 2010
my 2010 gl 350 is doing the same...i can floor it and it barely gets past 2 in the rpm gauge...i have to use the paddle shifters to change gears while accelerating otherwise it gets stuck before going up to the next geat...also notice it when slowing down...pedall to the floor and no power like before...did anybody figure out what the problems was
Thanks!
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GL350 2010
Fyi, I have replaced differential pressured and maf sensor and fuel filter and cleaned EGR, but the same issue still exist. I'm getting so frustrated with my GL350 bluetec 2010 since its oil cooler leaking. any inputs from your experience appreciated.
