*** Does your car "fall on its face" during part-throttle acceleration? ***
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From: Australia
03 E55 AMG
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From: Germany
SL65 R230
I had the "Load-Limit-Active" Problem on my pullied SLK32. It was difficult to reproduce, but happened mostly in cold weather, and only once during a drive, mostly after driving about 5 minutes. After the jerk, power seemed to be pulled back. After restart, the full power was back. In hot weather it was not there. Anyway, it was fixed on my car by reprogramming the EGS. Never came back again...
P.S. Error Code for "load-limit active" on my car was P20D4 not P2040D.
P.S. Error Code for "load-limit active" on my car was P20D4 not P2040D.
Last edited by AMG-Driver; Jan 20, 2009 at 02:52 AM.
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From: Australia
03 E55 AMG
i stand corrected on the air density part.
but here is a a perfect example for you of an E55 dumping boost with stock and aftermarket pullies. obviously boost should not drop off with the rpm rising as it would spin the blower faster and make more boost. but as you can see here in this boost log there is clearly a valve that dumps the boost....
but here is a a perfect example for you of an E55 dumping boost with stock and aftermarket pullies. obviously boost should not drop off with the rpm rising as it would spin the blower faster and make more boost. but as you can see here in this boost log there is clearly a valve that dumps the boost....
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From: Kuwait
CLS55 2006, CLS 63S 2015
As stated by marcus I have same symptoms. More apparent when I start the car for the first time on a new day and drive it under 1/4 or 1/2 throttle and it will hesitate and the whole car will jerk back and forth a few times. If I put my foot down from the start it will be less apparent
after driving for a while it doesnt happen again, or is hard to replicate
car is an o6
after driving for a while it doesnt happen again, or is hard to replicate
car is an o6
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'03 E55, Range Rover Sport Supercharged, Ducati 748R
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'10 Porsche Turbo PDK, 500e, GL450
+1
I have it on a 06 SLk55 with Renntech supercharger. I had this before the supercharger as well though.
Exactly the same as others have noted. Only happens with it is cold ... only happens before the car is fully warmed up. Extremely difficult to replicate. IN sunny california I can go months with out it happening.
Exactly the same as others have noted. Only happens with it is cold ... only happens before the car is fully warmed up. Extremely difficult to replicate. IN sunny california I can go months with out it happening.
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W221 S65 AMG
Victor,
Mine is actually a 2003 but nevertheless it has been doing this for ~2 years now. Its usually much worse in the cold. Sometimes it is so bad people ask what the hell is up with my driving as an abrupt cut in throttle actually feels like you are putting on the brakes abruptly. When I go into the dealership they are able to replicate it but say its probably faulty software from my tuner (K2 ecu tune from 2005) or due to the 80mm TB...I don't think they really have a clue.
I also told them NEVER to do the dreaded air pump flash and so far to my knowledge they have not. I do have the secondary air pump injection code pop up constantly. I can erase it but it will show back up no more than 30 miles later. Is this code the same as you are talking about? Code P2040D? I have a scanner so can go read this now.
Hey also I ran 126.6 :-) I need everything I can get!
This issue is probably one of the top 3 worst things about owning this car other than the weak transmission and lame steering wheel.
Mine is actually a 2003 but nevertheless it has been doing this for ~2 years now. Its usually much worse in the cold. Sometimes it is so bad people ask what the hell is up with my driving as an abrupt cut in throttle actually feels like you are putting on the brakes abruptly. When I go into the dealership they are able to replicate it but say its probably faulty software from my tuner (K2 ecu tune from 2005) or due to the 80mm TB...I don't think they really have a clue.
I also told them NEVER to do the dreaded air pump flash and so far to my knowledge they have not. I do have the secondary air pump injection code pop up constantly. I can erase it but it will show back up no more than 30 miles later. Is this code the same as you are talking about? Code P2040D? I have a scanner so can go read this now.
Hey also I ran 126.6 :-) I need everything I can get!
This issue is probably one of the top 3 worst things about owning this car other than the weak transmission and lame steering wheel.
There has been a behaviour that has been plaguing some member cars for many months. Some of you complained about the throttle flaps closing for a split second and then re-opening on you during part throttle acceleration.
This behaviour doesn't occur if you start off and go directly to WOT, but if you are cruising around at part throttle and try to accelerate you will likely run into this if you have this problem in your car.
This is not a mechanical problem. It is attributed to the dreaded "Secondary Airpump Recall Flash" that many people went through last year. During this campaign MB added some code which implemented load limiting. (I know this has been posted many times in the past, but I am reiterating because I have some new information.). I am not sure if some of the code falls over onto the EGS module or if it is isolated to the ECU only.
There is some data to suggest that some cars still haven't been able to get rid of this load limit problem.
How do you know if you have this problem? Very easy to find out:
1) Go onto a stretch of road and maintain a constant speed (say 50mph)
2) Slowly depress the accelerator and work your way to WOT.
3) At some point during this process you should feel a sudden jerk. The sensation will be like the throttle body flap suddenly closed shut on you for a split second but the car will then keep going on its way.
Now, take the car to someone with a STAR DAS device and do a "Quick Test" on all the function groups. If you have this problem, Code P2040D ("Load Limit Active") should be stored in your ME2.8.
The thing to remember here is if you do a dyno pull, or 1/4mile run, or anything where you are going WOT right away you will not notice this. This behaviour seems to be isolated to part throttle only.
Now for some data:
- My personal ECU with the original VRP tune that was developed on RFlow's car through Active Autowerke has this problem (Code is constantly presenting itself). My car is a 2003.
- E55 Baller has K2 programming and I am sure if he checks he will see he has this problem. We all know Isaac's car is strong because it ran an 11.11 @ 125mph. Isaac's car is a 2004.
- Marcus with his VR550 has this code stored (we just found out today) and his VRP tune is the newer one developed with Powerchip. His car runs strong and dyno'd well. Marcus has a 2005.
3 different tunes, 3 different years, all the same behaviour, so its not related to 1 particular tuner or year of vehicle.
I am sure there are more of you out there but you just don't know it. It's very interesting that these load limits are still present at part throttle driving even though they were effectively removed from the ECU code during the tuning process.
Nate's blistering E55 does not have this problem but I had a new EGS put on his car with all the load limits removed.
I purposely left my own ECU alone because I have been systematically going through everything on the car (mechanical and software related) to try and figure out the source. I have eliminated everything except for the EGS. I am waiting on my EGS to arrive from Germany with all the load limits removed on it like we did for Nate. Once I put this back in my car I will verify if the P2040D goes away.
Either the EGS alone will resolve this, or the EGS and ECU both have to be matched up and revised to completely eliminate the problem. I will post more data as I find it.
If any of you have this behaviour please post up.. I'd like to get a greater sampling of data to see what software you are running and what year your car is.
This behaviour doesn't occur if you start off and go directly to WOT, but if you are cruising around at part throttle and try to accelerate you will likely run into this if you have this problem in your car.
This is not a mechanical problem. It is attributed to the dreaded "Secondary Airpump Recall Flash" that many people went through last year. During this campaign MB added some code which implemented load limiting. (I know this has been posted many times in the past, but I am reiterating because I have some new information.). I am not sure if some of the code falls over onto the EGS module or if it is isolated to the ECU only.
There is some data to suggest that some cars still haven't been able to get rid of this load limit problem.
How do you know if you have this problem? Very easy to find out:
1) Go onto a stretch of road and maintain a constant speed (say 50mph)
2) Slowly depress the accelerator and work your way to WOT.
3) At some point during this process you should feel a sudden jerk. The sensation will be like the throttle body flap suddenly closed shut on you for a split second but the car will then keep going on its way.
Now, take the car to someone with a STAR DAS device and do a "Quick Test" on all the function groups. If you have this problem, Code P2040D ("Load Limit Active") should be stored in your ME2.8.
The thing to remember here is if you do a dyno pull, or 1/4mile run, or anything where you are going WOT right away you will not notice this. This behaviour seems to be isolated to part throttle only.
Now for some data:
- My personal ECU with the original VRP tune that was developed on RFlow's car through Active Autowerke has this problem (Code is constantly presenting itself). My car is a 2003.
- E55 Baller has K2 programming and I am sure if he checks he will see he has this problem. We all know Isaac's car is strong because it ran an 11.11 @ 125mph. Isaac's car is a 2004.
- Marcus with his VR550 has this code stored (we just found out today) and his VRP tune is the newer one developed with Powerchip. His car runs strong and dyno'd well. Marcus has a 2005.
3 different tunes, 3 different years, all the same behaviour, so its not related to 1 particular tuner or year of vehicle.
I am sure there are more of you out there but you just don't know it. It's very interesting that these load limits are still present at part throttle driving even though they were effectively removed from the ECU code during the tuning process.
Nate's blistering E55 does not have this problem but I had a new EGS put on his car with all the load limits removed.
I purposely left my own ECU alone because I have been systematically going through everything on the car (mechanical and software related) to try and figure out the source. I have eliminated everything except for the EGS. I am waiting on my EGS to arrive from Germany with all the load limits removed on it like we did for Nate. Once I put this back in my car I will verify if the P2040D goes away.
Either the EGS alone will resolve this, or the EGS and ECU both have to be matched up and revised to completely eliminate the problem. I will post more data as I find it.
If any of you have this behaviour please post up.. I'd like to get a greater sampling of data to see what software you are running and what year your car is.
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Real Cars
Here's a thought/discussion point - and maybe E55Pilot can shed his knowledge of the ME2.8. I was talking to DSMED about this issue and he mentioned the topic of closed-loop versus open-loop operation. (for those of you who want to learn a very important part of EFI engineering, check out this article - http://www.musclemustangfastfords.co...l_control.html). I am curious if ME 2.8 has any special "tricks" when it comes to CL vs OL operation? Does the TCU have any say in regards to when the car switches from OL to CL operation? How does ME 2.8 calculate load? What is the ME 2.8 looking at (sensor-wise) in OL?
It seems to me that this is something that is relegated to OL, although I admit that may not necessarily be the reason for it happening, it may help whittle down the list of explanations.
-m
It seems to me that this is something that is relegated to OL, although I admit that may not necessarily be the reason for it happening, it may help whittle down the list of explanations.
-m
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Joined: May 2008
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From: Aberdeen, MD
CLA
I had the "Load-Limit-Active" Problem on my pullied SLK32. It was difficult to reproduce, but happened mostly in cold weather, and only once during a drive, mostly after driving about 5 minutes. After the jerk, power seemed to be pulled back. After restart, the full power was back. In hot weather it was not there. Anyway, it was fixed on my car by reprogramming the EGS. Never came back again...
P.S. Error Code for "load-limit active" on my car was P20D4 not P2040D.
P.S. Error Code for "load-limit active" on my car was P20D4 not P2040D.
TTT
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2004 E55
Here's a thought/discussion point - and maybe E55Pilot can shed his knowledge of the ME2.8. I was talking to DSMED about this issue and he mentioned the topic of closed-loop versus open-loop operation. (for those of you who want to learn a very important part of EFI engineering, check out this article - http://www.musclemustangfastfords.co...l_control.html). I am curious if ME 2.8 has any special "tricks" when it comes to CL vs OL operation? Does the TCU have any say in regards to when the car switches from OL to CL operation? How does ME 2.8 calculate load? What is the ME 2.8 looking at (sensor-wise) in OL?
It seems to me that this is something that is relegated to OL, although I admit that may not necessarily be the reason for it happening, it may help whittle down the list of explanations.
-m
It seems to me that this is something that is relegated to OL, although I admit that may not necessarily be the reason for it happening, it may help whittle down the list of explanations.
-m
Remember in a Speed Density system once you go open loop you are on the "Math Motor" and anything done to change the motors VE (Flow) will confuse the ECU
One other thought, Everyone here is complaining that the motor is doing this while still not fully warmed up. Without having poked around in the ECU too much I'm not sure if there is a warmup load table that will prevent you from hammering the motor until the oil has reached at least 165-185F.
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From: Westchester, NY
E55, C32, ML320
I think I was in 3rd or 4th gear going up a hill at about 2500 RPM with a bit more than moderate acceleration. I was actually trying to drive in a balanced manner (avoiding downshift) since I knew the car wasn't warmed up. Maybe I was in too high a gear for the incline/speed or as another poster said, the air was so cold it was making additional power?
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2004 E55
I think I was in 3rd or 4th gear going up a hill at about 2500 RPM with a bit more than moderate acceleration. I was actually trying to drive in a balanced manner (avoiding downshift) since I knew the car wasn't warmed up. Maybe I was in too high a gear for the incline/speed or as another poster said, the air was so cold it was making additional power?
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From: Australia
03 E55 AMG
One other thought, Everyone here is complaining that the motor is doing this while still not fully warmed up. Without having poked around in the ECU too much I'm not sure if there is a warmup load table that will prevent you from hammering the motor until the oil has reached at least 165-185F.
Thread Starter
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From: Richmond Hill, Ontario
2003 E55 AMG
Those of you that have this problem, please go through the procedure that you normally follow when you want to put the car into DYNO MODE.
Once you enter that engineering menu the main screen you land on will have some information like your VIN#, the HW # and SW #.
Please write down your HW (Hardware #) and SW (Software #) and post it up here. This will tell us which revision # you are currently using.
I am pretty sure we can isolate this with enough samples.
I was able to obtain a stock BIN of the 55's EEPROM code which I know does not have the load limiting software.
The Revision returned from the Bosche ME2.8 was :
HW: 026 120 8106
SW: 103 736 5088
This is from an 03-04 car which never had any updates performed. We know load limiting was introduced in 2005 and then applied to all previous cars through the recall.
These revision # will be different than what the instrument cluster will display but there is a correlation between the 2.
I am expecting my EGS this week so I'll check and see if that removes the issue for me.
Once you enter that engineering menu the main screen you land on will have some information like your VIN#, the HW # and SW #.
Please write down your HW (Hardware #) and SW (Software #) and post it up here. This will tell us which revision # you are currently using.
I am pretty sure we can isolate this with enough samples.
I was able to obtain a stock BIN of the 55's EEPROM code which I know does not have the load limiting software.
The Revision returned from the Bosche ME2.8 was :
HW: 026 120 8106
SW: 103 736 5088
This is from an 03-04 car which never had any updates performed. We know load limiting was introduced in 2005 and then applied to all previous cars through the recall.
These revision # will be different than what the instrument cluster will display but there is a correlation between the 2.
I am expecting my EGS this week so I'll check and see if that removes the issue for me.
Thread Starter
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From: Richmond Hill, Ontario
2003 E55 AMG
Forgot one thing... The issue some of you are seeing with temperature is only because of the power output your car has. The more the car makes the easier it will be to "trip" this load limit and have this problem..
Guys with fully built cars like myself, Issac and Finny will have this problem more often.. My car does it in the dead of summer (32C) or winter.
Guys with fully built cars like myself, Issac and Finny will have this problem more often.. My car does it in the dead of summer (32C) or winter.
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E-ZGO 53hp., 1999 E 430 sport, 2004 E 55, 2008 Tahoe LTZ on 24"s
The proverbial holy binary grail. Victor in the early days of the "Detune the 55s the 63s are coming out" days (AKA air pump recall). The hush hush low down talk between tuners (K,RT) was that MB/AMG had installed a lock that would prevent a re-flash back to the original SW. Has this proved out?
I'll post up my numbers next week.
I'll post up my numbers next week.
Last edited by Yacht Master; Jan 20, 2009 at 12:53 PM.
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From: Germany
SL65 R230
This problem was fixed by setting the torque-limit in the EGS higher. Don't know exactly how it is stored there, you have to change some values.The ECU has to interact correctly with the EGS. This was not the case before it was reprogrammed! At the same time the shifting-times were programmed a little quicker. I am satisfied now, the jerk and P20D4 never came back and the car has great power again without any problems.
Thread Starter
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From: Richmond Hill, Ontario
2003 E55 AMG
I dont think so.. Or at least its not an issue anymore.
Our customers that have had VRP flashes done through Powerchip have had the load limits completely removed. We showed this in the posting we did during the VR550 development cycle. Vadim posted graphs of Jangy's car which showed the load limits engaging on the dyno and power output being killed.. Then, once the software was updated to remove those limits, Vadim did another pull and the power output increased quite a bit.
The only puzzling thing here is why some cars still have "remnants" of this issue popping up when the ECU was reprogrammed to do away with the limits.
I will get something in Powerchip's hands so Jeremy can poke around and see if he can figure out what is going on. My goal for my own personal knowledge is to understand exactly what this recall did, and how it affects these different cars.. I'm just very curious about the whole thing.
Our customers that have had VRP flashes done through Powerchip have had the load limits completely removed. We showed this in the posting we did during the VR550 development cycle. Vadim posted graphs of Jangy's car which showed the load limits engaging on the dyno and power output being killed.. Then, once the software was updated to remove those limits, Vadim did another pull and the power output increased quite a bit.
The only puzzling thing here is why some cars still have "remnants" of this issue popping up when the ECU was reprogrammed to do away with the limits.
I will get something in Powerchip's hands so Jeremy can poke around and see if he can figure out what is going on. My goal for my own personal knowledge is to understand exactly what this recall did, and how it affects these different cars.. I'm just very curious about the whole thing.
The proverbial holy binary grail. Victor in the early days of the "Detune the 55s the 63s are coming out" days (AKA air pump recall). The hush hush low down talk between tuners (K,RT) was that MB/AMG had installed a lock that would prevent a re-flash back to the original SW. Has this proved out?
