GM 12592525 Map Issue

[Webbs]

I have two vehicles in my shop and both of them will not correctly read. At key hot they are both reading 26kpa? the offset and scaler are correct and I use these all the time? Is something not address correctly in the new update ? Anyone else having or had this issue?

W~

[joecar]

Post log files.

[Webbs]

Here is a copy of the tune and a log file. In the log file I tried cranking the car a few times to see what the MAP would do and obviously the car does not start. This really makes no sense!! :wallbash:

w~

1518015181

[joecar]

Is the 3-bar MAP sensor physically installed...? It looks like from the log it is not (tune file is scaled for 3-bar, but SAE.MAP pid shows 1/3 of BARO).

[Webbs]

Yes it's installed in the stock LS3 location.

[joecar]

Hmmm... IDK what is wrong.

[joecar]

What happens if in the tune you change the MAP scaler... in the scantool does SAE.MAP still read the same 27 kPa or does it read different...?

[limited cv8r]

Coppied from custom upgrade PDF
Configuring a 2 or 3-bar MAP sensor
When the key is on but the engine is not running, the MAP sensor reads the barometric air pressure, usually 101kPa (14.7psi). When tuning in high altitude areas it is worthwhile reading the MAP values (using EFILive’s Scan Tool) at key-on with the standard 1-bar sensor to obtain the barometric pressure at the current altitude. After fitting your 2 or 3-bar MAP sensor, you must rescale the MAP sensor.

Engine Diagnostics->MAP->Parameters

•

{C6301} MAP Sensor Scaler: 2-bar sensor: 190 3-bar sensor: 288
　

These values will get the MAP scaler’s value close to what it needs to be, you will then need to adjust it (by small amounts) until the MAP sensor reads the same barometric pressure that your standard 1-bar sensor was reading at key-on, engine-off.
Logging boost levels in the Scan Tool must be performed with the PID ‘SAE.MAP’.

[Webbs]

Coppied from custom upgrade PDF
Configuring a 2 or 3-bar MAP sensor
When the key is on but the engine is not running, the MAP sensor reads the barometric air pressure, usually 101kPa (14.7psi). When tuning in high altitude areas it is worthwhile reading the MAP values (using EFILive’s Scan Tool) at key-on with the standard 1-bar sensor to obtain the barometric pressure at the current altitude. After fitting your 2 or 3-bar MAP sensor, you must rescale the MAP sensor.

Engine Diagnostics->MAP->Parameters

•

{C6301} MAP Sensor Scaler: 2-bar sensor: 190 3-bar sensor: 288
　

These values will get the MAP scaler’s value close to what it needs to be, you will then need to adjust it (by small amounts) until the MAP sensor reads the same barometric pressure that your standard 1-bar sensor was reading at key-on, engine-off.
Logging boost levels in the Scan Tool must be performed with the PID ‘SAE.MAP’.



I understand what you are saying but when you have the correct data for offset/scaler from GM why would you use anything else to start from. Also I have used the same data in quite a few cars with no issues. That is why it is not making sense. It's not like I'm breaking new ground with some off the wall idea may people use the same sensor and data.

[Webbs]

What happens if in the tune you change the MAP scaler... in the scantool does SAE.MAP still read the same 27 kPa or does it read different...?


With the stock offset/scaler it shows 42kpa,.

[darcy]

That tune has a Scalar of 312.5 and Offset of -77.5625.

Shouldn't it be more like 288 & 27 for 3-bar sensor?

[darcy]

Actually, I just had a poke around the 'net, the offset and scalar for that MAP sensor look to be 312.5 & -11.25
http://www.jdpmotorsports.com/genuine-gm-zr1-3-bar-map-sensor-12592525

That would put your koeo reading at 92kPa - Is that logical for where you are located, Webbs?

[joecar]

An offset of -77 seems wrong... should be closer to zero (which is what -11 is).

[Webbs]

Well I finally figured out what the issue was. It was the loose nut behind the keyboard!!! :cussing::doh: After review I noticed that B2103 was in PSI not KPA. When I loaded the latest update it reverted back to imperial settings so when I went through and loaded in the offset as -11.25 thinking it was KPA and I actually was putting in -11.25 PSI. Whooo hooo Yea me!! lol


W~

[joecar]

Yeah, units will do that...