Map sensor question
Thread Starter
Joined: Jan 2009
Posts: 1,106
Likes: 85
From: Lebanon
Cls63 & C32
Map sensor question
Is there any 3 bars mercedes map sensor?
our stock map sensor is 2.5 bar absolute pressure, so when we hit the 1.5 bars boost we get the high pressure code p0108.
i have a v6 3.7L with 55SC, with stock pulleys i was at 1.4-1.5 bars, car was tuned with 550cc and running good, now with 175mm lower, 84 upper and 750cc injectors (waiting for tune) the car hit the 1.5 bars at 2500/3000 rpm and cuts fuel cause i pass the map sensor limit and give p0172 system too rich codes and p0108 high pressure.
our stock map sensor is 2.5 bar absolute pressure, so when we hit the 1.5 bars boost we get the high pressure code p0108.
i have a v6 3.7L with 55SC, with stock pulleys i was at 1.4-1.5 bars, car was tuned with 550cc and running good, now with 175mm lower, 84 upper and 750cc injectors (waiting for tune) the car hit the 1.5 bars at 2500/3000 rpm and cuts fuel cause i pass the map sensor limit and give p0172 system too rich codes and p0108 high pressure.
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shrimp boat
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From: San Diego
F-250
Only problem with re-scaling: Good luck finding anyone that can do it on our platform: and make the car work (drivable)....
I pulled the upper pulley because I could not get a tuner to fix the issue: Over-boost Cut Out
I was going to build a MAP clamp, but finally just said **** it...
I pulled the upper pulley because I could not get a tuner to fix the issue: Over-boost Cut Out
I was going to build a MAP clamp, but finally just said **** it...
Thread Starter
Joined: Jan 2009
Posts: 1,106
Likes: 85
From: Lebanon
Cls63 & C32
Only problem with re-scaling: Good luck finding anyone that can do it on our platform: and make the car work (drivable)....
I pulled the upper pulley because I could not get a tuner to fix the issue: Over-boost Cut Out
I was going to build a MAP clamp, but finally just said **** it...
I pulled the upper pulley because I could not get a tuner to fix the issue: Over-boost Cut Out
I was going to build a MAP clamp, but finally just said **** it...
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Senior Member
Joined: Aug 2009
Posts: 310
Likes: 1
From: Wisconsin
2005 E55, 2007 ML63, 2008 SLK, 2015 GLK350, BMW Z3, Dodge Power Wagon, Electric Smart car
Is there any 3 bars mercedes map sensor?
our stock map sensor is 2.5 bar absolute pressure, so when we hit the 1.5 bars boost we get the high pressure code p0108.
i have a v6 3.7L with 55SC, with stock pulleys i was at 1.4-1.5 bars, car was tuned with 550cc and running good, now with 175mm lower, 84 upper and 750cc injectors (waiting for tune) the car hit the 1.5 bars at 2500/3000 rpm and cuts fuel cause i pass the map sensor limit and give p0172 system too rich codes and p0108 high pressure.
our stock map sensor is 2.5 bar absolute pressure, so when we hit the 1.5 bars boost we get the high pressure code p0108.
i have a v6 3.7L with 55SC, with stock pulleys i was at 1.4-1.5 bars, car was tuned with 550cc and running good, now with 175mm lower, 84 upper and 750cc injectors (waiting for tune) the car hit the 1.5 bars at 2500/3000 rpm and cuts fuel cause i pass the map sensor limit and give p0172 system too rich codes and p0108 high pressure.
I read on another forum.....
"I also have found a 3 bar MAP for our cars that is plug and play but would need tune scaling. The new 320/350 Diesel has the 3 bar MAP."
Maybe this will help?
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Joined: Mar 2004
Posts: 2,073
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From: North NJ
2002 C32 AMG, 2013 GLK 350/4, 2015 E63S AMG Wagon
The question remains. Who can program the ECU to see the extra boost and react accordingly?
Super Member
Joined: Mar 2011
Posts: 502
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From: Porter Ranch, CA
E55, CTS-V Wagon, Duc 1098R
Look up Map Clamp. You can run one so that when the map exceeds the voltage, it will still send the max allowable to the ECU and avoid the code. Split second performance and many others make them. Because our cars are speed density, the car is still tunable this way but you will need to do pulls not only at WOT, but also at slightly lower throttle positions until the clamp is inactive to get it to run perfect. It won't run bad if you choose not to do the part throttle pulls, but it will likely be rich.
Super Member
Joined: Mar 2011
Posts: 502
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From: Porter Ranch, CA
E55, CTS-V Wagon, Duc 1098R
This will require remapping all the tables associated with the map sensor which are most of them. In other words, the risk is big. Talk to your tuner about it and see what they think.
I really think you need to consider a map clamp or a signal calibrator (see link below) since it will only be active when you are above approximately 17.5 psi. That is typically where the ECU hits the limit and shuts the fuel off. In all other cases, your existing tune will be untouched and therefore you can tune as you have initially suggested.
http://www.splitsec.com/products/calibrators2.htm
Thread Starter
Joined: Jan 2009
Posts: 1,106
Likes: 85
From: Lebanon
Cls63 & C32
This will require remapping all the tables associated with the map sensor which are most of them. In other words, the risk is big. Talk to your tuner about it and see what they think.
I really think you need to consider a map clamp or a signal calibrator (see link below) since it will only be active when you are above approximately 17.5 psi. That is typically where the ECU hits the limit and shuts the fuel off. In all other cases, your existing tune will be untouched and therefore you can tune as you have initially suggested.
http://www.splitsec.com/products/calibrators2.htm
I really think you need to consider a map clamp or a signal calibrator (see link below) since it will only be active when you are above approximately 17.5 psi. That is typically where the ECU hits the limit and shuts the fuel off. In all other cases, your existing tune will be untouched and therefore you can tune as you have initially suggested.
http://www.splitsec.com/products/calibrators2.htm
our ecu cut fuel only above 1.5 bar(22-23psi), many times before i went to 1.4 and 1.5 bars, it only gives code high boost, but now when i hit past 1.5 bars it cuts fuel.
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Joined: Mar 2004
Posts: 2,073
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From: North NJ
2002 C32 AMG, 2013 GLK 350/4, 2015 E63S AMG Wagon
This will require remapping all the tables associated with the map sensor which are most of them. In other words, the risk is big. Talk to your tuner about it and see what they think.
I really think you need to consider a map clamp or a signal calibrator (see link below) since it will only be active when you are above approximately 17.5 psi. That is typically where the ECU hits the limit and shuts the fuel off. In all other cases, your existing tune will be untouched and therefore you can tune as you have initially suggested.
http://www.splitsec.com/products/calibrators2.htm
I really think you need to consider a map clamp or a signal calibrator (see link below) since it will only be active when you are above approximately 17.5 psi. That is typically where the ECU hits the limit and shuts the fuel off. In all other cases, your existing tune will be untouched and therefore you can tune as you have initially suggested.
http://www.splitsec.com/products/calibrators2.htm
Thread Starter
Joined: Jan 2009
Posts: 1,106
Likes: 85
From: Lebanon
Cls63 & C32
so if we don't rescale the 0-5v map signal(with the bigger map), the ecu read lower boost and the fuel quantity will be lower, then we add necessary fuel by tuning, is there any problem??
ex: if the map voltage at 3v the ecu will see like 1bar but actually the boost is at like 1.5 bars.
ex: if the map voltage at 3v the ecu will see like 1bar but actually the boost is at like 1.5 bars.
MBWorld Fanatic!
Joined: Mar 2004
Posts: 2,073
Likes: 27
From: North NJ
2002 C32 AMG, 2013 GLK 350/4, 2015 E63S AMG Wagon
so if we don't rescale the 0-5v map signal(with the bigger map), the ecu read lower boost and the fuel quantity will be lower, then we add necessary fuel by tuning, is there any problem??
ex: if the map voltage at 3v the ecu will see like 1bar but actually the boost is at like 1.5 bars.
ex: if the map voltage at 3v the ecu will see like 1bar but actually the boost is at like 1.5 bars.
Super Member
Joined: Oct 2013
Posts: 745
Likes: 139
14 E63, 05 E55, 03 Evo 8, 08 F250, 06 R6R, 92 Talon TSI, and instability
Did you do anything with the MAP scaling or did you simply throw the new sensor on? Let me guess, It probably cranked, started, and died right?
Thread Starter
Joined: Jan 2009
Posts: 1,106
Likes: 85
From: Lebanon
Cls63 & C32
Super Member
Joined: Oct 2013
Posts: 745
Likes: 139
14 E63, 05 E55, 03 Evo 8, 08 F250, 06 R6R, 92 Talon TSI, and instability
That's exactly what I expected. The reason is because the ecu does not know how to interpret what the larger map is telling it. Once it is rescaled, it will do just fine, but it has to know how to interpret what the sensor is telling it.
Super Member
Joined: Oct 2013
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14 E63, 05 E55, 03 Evo 8, 08 F250, 06 R6R, 92 Talon TSI, and instability
As an arbitrary example, 0v equals no signal, but everything from 0.1-5v does not equal the same. The ecu is seeing a value above or (most likely) below what it is expecting to see and is interpreting it as a potentially catastrophic situation.
Thread Starter
Joined: Jan 2009
Posts: 1,106
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From: Lebanon
Cls63 & C32
yap but like Bramage said no one can rescale it!
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Joined: Oct 2013
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14 E63, 05 E55, 03 Evo 8, 08 F250, 06 R6R, 92 Talon TSI, and instability
I call BS and say that no one has taken the time to play with MAP scaling. Half the battle has been accomplished in that a 0-5v sensor does exist that fits. Now we just need to either find a tuner that's willing to play, or get your hands on the software/hardware necessary to edit the values.
