LML Map sensor max

delong_1

<< my work
Dec 5, 2008
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Arvada, CO
I tried finding the info but came up with nothing. How high does the factory map sensor read? Trying to plan some gauge stuff
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
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Wyoming
The LML sensor reads up to 53psi absolute.

So 38 psi actual boost at sea level, say 40psi boost for you in Colorado.

The ECM also calculates boost internally based on load, speed, turbo speed, etc and then uses as a sanity check on the MAP sensor.

Ben
 

kiwilml

Member
Nov 4, 2015
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So it would be complicated to have a map delete tune wrote huh?

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IOWA LLY

Yes, its really me
Feb 23, 2007
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Why would you want a map delete tune?

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kiwilml

Member
Nov 4, 2015
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Oh just thinking if couldn't find my problem with it that could just delete it but I have absolutely no clue how that would drive or work.. Was just curious mainly
 

DAVe3283

Heavy & Slow
Sep 3, 2009
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Boise, ID, USA
In theory, a tune could be written without a MAP sensor, but it would remove a lot of safety/sanity checks that could cause a minor problem to end up hurting the turbo. Though not much of the LML is mapped (AFAIK) so it might not yet be possible to do a MAP delete tune.

I think you are best served by sorting out the root problem, especially at this stage in the game of LML tuning. Though I like to keep all sensors operating on principle, but that's the engineer in me talking.
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
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It would be next to impossible to have any duramax from LLY to LML that still has a VVT style turbo without a MAP sensor. Not saying you couldn't do it, but I don't think it would work very well.
 

kiwilml

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Nov 4, 2015
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Well I have a fixed vane single turbo but yeah I'm definitely gonna try to find out what the problem is before I would pursue this..
 

JoshH

Daggum farm truck
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Vendor/Sponsor
Feb 14, 2007
13,599
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Texas!!!
Well I have a fixed vane single turbo but yeah I'm definitely gonna try to find out what the problem is before I would pursue this..
Shouldn't be a problem then. I never even looked at your signature. What is the truck doing or not doing, and have you talked with Kory about it?
 

kiwilml

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Nov 4, 2015
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No I haven't talked to Kory because I don't think it's a tuning issue. I watch my MAP pressure on cts and once every thing gets all hot it'll start going all over the place and when I'm cruising I can hear motor change sound and actually feel it even.

Did this a few weeks ago and so I changed sensor and it was normal reading for a week or so and now started doing same thing again..
 

kiwilml

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Nov 4, 2015
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I wondered about that, I don't really want it any dirtier than already is.. Can be pretty bad now
 

DAVe3283

Heavy & Slow
Sep 3, 2009
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Boise, ID, USA
If you are feeling & hearing the power output change when the MAP reading varies, it really sounds like the boost is changing. You can try adding a mechanical boost gauge to see if it does the same thing. If so, there might be a heat related leak? Maybe a coupler gets soft and starts to leak??

There is some weirdness in the newer motors (LMM+) with how they read & report MAP, so I would be tempted to plumb in a mechanical gauge temporarily to verify it is or isn't the ECU being weird.
 

kiwilml

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Nov 4, 2015
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I do have a separate boost gauge on the pillar, it don't fluctuate. I definitely think it's an electrical problem and I might try another sensor just in case this new one is bad already.. It was an ac Delco brand and thought that was supposed to be a good one..

I wonder what brand it is if I'd get one through the dealer?
 

kiwilml

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Nov 4, 2015
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Got a new sensor on and it's been doing good all week..

And yeah my boost gauge is electric..