View Poll Results: Do you have the hiccup issue? Vote your Modelyear and Mods
E55 Modelyear 2003 with ONLY 82mm TB mod
0
0%
E55 Modelyear 2004 with ONLY 82mm TB mod
0
0%
E55 Modelyear 2005 with ONLY 82mm TB mod
0
0%
E55 Modelyear 2006 with ONLY 82mm TB mod
0
0%
OTHER 55K AMG with ONLY 82mm TB mod
0
0%
Multiple Choice Poll. Voters: 18. You may not vote on this poll
Hiccup Issue - The Poll
SPONSOR
Joined: Jul 2016
Posts: 3,024
Likes: 395
From: Colorado, USA
E55 C63
This seems to be a better thread than the other for this discussion so here is the consolidation of information for this issue.
This issue has been documented with IQ tunes, Vtech tunes, EC tunes, as well as some private tuners.
The issue is not exclusively related to a vacuum leak
The issue occurs on cars with and without a bypass valves
The issue is more pronounced with larger throttle bodies
The issue has been documented with stock TBs, 80mm, 82mm, 92mm, and 105mm.
Throttle bodies have been swapped which has not eliminated the issue.
The issue is not definitively related to certain throttle positions or Map readings
Map Clamp has not eliminated the issue.
The issue resets with a cycle of the key
A test of the 5v constant at the Map sensor tested out to 5v on a car with the issue meaning another sensor in the circuit is not back feeding and messing up the reference.
Replacing IAT or Map sensor does not resolve the issue.
This issue is not related to TCU tune
The characteristics of the issue are a "Lean condition developed after a period of time driving. The vehicle will stay lean under load and under idle until the key is cycled. The condition will go away temporarily but will re-appear shortly after after put under load.
The issue gets progressively worse over time, going from 20-30 minutes of drive time, to almost instantly under certain conditions, which leans towards a degradation of a component, or a “memory” overload in ECU maybe due to storing error codes over time
There is no confirmation that Varying ME versions effect who does or doesn’t get the error.
The Safety "map" seems to be the most widely believed reasoning for this Issue.
This issue has been documented with IQ tunes, Vtech tunes, EC tunes, as well as some private tuners.
The issue is not exclusively related to a vacuum leak
The issue occurs on cars with and without a bypass valves
The issue is more pronounced with larger throttle bodies
The issue has been documented with stock TBs, 80mm, 82mm, 92mm, and 105mm.
Throttle bodies have been swapped which has not eliminated the issue.
The issue is not definitively related to certain throttle positions or Map readings
Map Clamp has not eliminated the issue.
The issue resets with a cycle of the key
A test of the 5v constant at the Map sensor tested out to 5v on a car with the issue meaning another sensor in the circuit is not back feeding and messing up the reference.
Replacing IAT or Map sensor does not resolve the issue.
This issue is not related to TCU tune
The characteristics of the issue are a "Lean condition developed after a period of time driving. The vehicle will stay lean under load and under idle until the key is cycled. The condition will go away temporarily but will re-appear shortly after after put under load.
The issue gets progressively worse over time, going from 20-30 minutes of drive time, to almost instantly under certain conditions, which leans towards a degradation of a component, or a “memory” overload in ECU maybe due to storing error codes over time
There is no confirmation that Varying ME versions effect who does or doesn’t get the error.
The Safety "map" seems to be the most widely believed reasoning for this Issue.
Newbie
Joined: May 2023
Posts: 2
Likes: 0
C220 cdi
This seems to be a better thread than the other for this discussion so here is the consolidation of information for this issue.
This issue has been documented with IQ tunes, Vtech tunes, EC tunes, as well as some private tuners.
The issue is not exclusively related to a vacuum leak
The issue occurs on cars with and without a bypass valves
The issue is more pronounced with larger throttle bodies
The issue has been documented with stock TBs, 80mm, 82mm, 92mm, and 105mm.
Throttle bodies have been swapped which has not eliminated the issue.
The issue is not definitively related to certain throttle positions or Map readings
Map Clamp has not eliminated the issue.
The issue resets with a cycle of the key
A test of the 5v constant at the Map sensor tested out to 5v on a car with the issue meaning another sensor in the circuit is not back feeding and messing up the reference.
Replacing IAT or Map sensor does not resolve the issue.
This issue is not related to TCU tune
The characteristics of the issue are a "Lean condition developed after a period of time driving. The vehicle will stay lean under load and under idle until the key is cycled. The condition will go away temporarily but will re-appear shortly after after put under load.
The issue gets progressively worse over time, going from 20-30 minutes of drive time, to almost instantly under certain conditions, which leans towards a degradation of a component, or a “memory” overload in ECU maybe due to storing error codes over time
There is no confirmation that Varying ME versions effect who does or doesn’t get the error.
The Safety "map" seems to be the most widely believed reasoning for this Issue.
This issue has been documented with IQ tunes, Vtech tunes, EC tunes, as well as some private tuners.
The issue is not exclusively related to a vacuum leak
The issue occurs on cars with and without a bypass valves
The issue is more pronounced with larger throttle bodies
The issue has been documented with stock TBs, 80mm, 82mm, 92mm, and 105mm.
Throttle bodies have been swapped which has not eliminated the issue.
The issue is not definitively related to certain throttle positions or Map readings
Map Clamp has not eliminated the issue.
The issue resets with a cycle of the key
A test of the 5v constant at the Map sensor tested out to 5v on a car with the issue meaning another sensor in the circuit is not back feeding and messing up the reference.
Replacing IAT or Map sensor does not resolve the issue.
This issue is not related to TCU tune
The characteristics of the issue are a "Lean condition developed after a period of time driving. The vehicle will stay lean under load and under idle until the key is cycled. The condition will go away temporarily but will re-appear shortly after after put under load.
The issue gets progressively worse over time, going from 20-30 minutes of drive time, to almost instantly under certain conditions, which leans towards a degradation of a component, or a “memory” overload in ECU maybe due to storing error codes over time
There is no confirmation that Varying ME versions effect who does or doesn’t get the error.
The Safety "map" seems to be the most widely believed reasoning for this Issue.
Was this ever solved?
Senior Member
Joined: Nov 2018
Posts: 335
Likes: 54
CLS55 AMG
Newbie
Joined: May 2023
Posts: 2
Likes: 0
C220 cdi
I don't plan going back to 74mm TB.
The thing is that I am familiar with bosch motronic engine management systems and I think I have found the fail safe maps mentioned in this forum. Also I have found single value maps that can affect "giong into fail safe mode.
My theory is the following:
All Bosch Motronic systems are measuring amount Air entering the engine. No matter MAF or MAP and their location. If the sensor that is measuring Air entering the engine fails, in all Motronic systems I am familiar with, actually is triggered a fail safe algorithm to determine somehow the amount of air entering the engine. What I saw from looking at different Bosch Motronic versions is that the ECU is calculating air entering the engine mainly from TB angle. \
From my point of view this is in ME2.8.1 in same way. There is also one very interesting factor, I am referring to ME7 in this case. According to the Funktionsrahmen of that ECU, Sometimes ECU is switching to modeled load signal because of implausibility of main load signal(in case of ME7 is the MAF, in case of ME2.8.1 is MAP). Now if this two load signals are not similar ME7 does not care(it does not affect the driving like it is in me2.8.1)
it is a problem only if the MAF fails.
It looks like ME2.8.1 cares a lot about this two signals being similar.
In theory ME2.8.1 should run without MAP sensor with no hiccups if TB maps are calibrated correctly.
I will test mentioned above and report. As I have said earlier I think I have found the maps that are responsible for fail safe and the Switching to modeled load signal.
The thing is that I am familiar with bosch motronic engine management systems and I think I have found the fail safe maps mentioned in this forum. Also I have found single value maps that can affect "giong into fail safe mode.
My theory is the following:
All Bosch Motronic systems are measuring amount Air entering the engine. No matter MAF or MAP and their location. If the sensor that is measuring Air entering the engine fails, in all Motronic systems I am familiar with, actually is triggered a fail safe algorithm to determine somehow the amount of air entering the engine. What I saw from looking at different Bosch Motronic versions is that the ECU is calculating air entering the engine mainly from TB angle. \
From my point of view this is in ME2.8.1 in same way. There is also one very interesting factor, I am referring to ME7 in this case. According to the Funktionsrahmen of that ECU, Sometimes ECU is switching to modeled load signal because of implausibility of main load signal(in case of ME7 is the MAF, in case of ME2.8.1 is MAP). Now if this two load signals are not similar ME7 does not care(it does not affect the driving like it is in me2.8.1)
it is a problem only if the MAF fails.It looks like ME2.8.1 cares a lot about this two signals being similar.
In theory ME2.8.1 should run without MAP sensor with no hiccups if TB maps are calibrated correctly.
I will test mentioned above and report. As I have said earlier I think I have found the maps that are responsible for fail safe and the Switching to modeled load signal.
