MAP sensor reading off? 1 or 2 bar?

[kaliney65]

I completed a swap using a LY6 engine , 4L80E trans, E38 pcm from a 08 3500 express into my 02 camaro.

My understanding is that the van would use a 1 bar map since it was N/A and based on research of the P/N 09359409 and the fact that the factory settings were linear 94.43 and offset 10.34 i believed it was a 1 bar map. Since im turbocharged now i knew i would need to upgrade to a 2 bar map at minimum.

I was getting 102 kpa with key on engine off on the VCM scanner at about 60kpa at idle to do some idle tuning which worked and pushed me more to believe it was a 1 bar map.

I wanted to do some road tuning and didnt want to chance getting into boost on a 1 bar map so i switched over to the 2bar os and installed a new map sensor P/N 12614970 which was suposed to be a 2 bar sensor with linear 200 and offset 10.34 settings and got 205kpa on the scanner with key on engine off.

So that led me to check the voltage on the new map which was 4.8v key on engine off. The original map was about 2.6v key on engine off which makes me believe i had a 2 bar in the first place.

Ive done about 20 hours looking around various forums and sites and accepted that the new map i bought is a 1 bar because of the 4.8v key on engine off and im out of that money but this brings the question.

Why would that map sensor show 100 kpa on the scanner key on engine off with 94.43 linear (5v) and 10.34 offset (0v) with 2.5 volts? Shouldnt it have shown around 55-65kpa at 2.5v with the linear and offset settings?

[Lakegoat]

I don't believe that number is a 2 bar map sensor. Here is a correct number: 12615136

[kaliney65]

Thanks for the reply. Im just now seeing the message. First post here on the hp tuners forum. Ill give that part number a try. It just blows my mind that i have 2 different maps one showing 2.5v and another showing 4.8v both KOEO with the same scanner kpa readings. Around 100kpa on a 1 bar OS and 205kpa on the 2 bar OS.

[Lakegoat]

If you applied the 2 bar OS, it auto changes the MAP data to 2 bar. If you used the stock 1 bar or put in another 1 bar, the reading will be off because of the wrong data.

[Paoloz]

can you share the map? I have a E38 3500 I want to upgrade to two bar sensor