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Map sensor not reading

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Old Aug 12, 2017 | 05:13 PM
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Default Map sensor not reading

Hey guys. I need some help with a map sensor not reading. It's a 5.3 and 6l80e from a 2009 silverado. Ecm is from the same drivetrain but harness was not good and i got a harness from a 2008 sierra with a 6.2/6l80e. All that is in a 88 c1500 and i made the harness myself to make it work. Apperantly everything else works except the map sensor is not reading. Scanner shows 10 kpa with key on engine off. I get 5v in the reference wire on the map plug with it unplugged and nothing on the other wires. Once map is plugged in i get 5v in all 3 wires which sounds weird to me. Tried 3 different map sensors, tried running another set of wires fron the ecm to the sensor with no luck. Also unplugged every other sensor to see if any sensor was bad that would maybe interfere with the map but still only get 10 kpa in the scanner. Any help would be appreciated. I need to get this truck running ASAP.
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Old Aug 12, 2017 | 05:19 PM
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From: Little Austin
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Double check the pinouts on the MAP plug.

Andrew
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Old Aug 12, 2017 | 09:44 PM
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I already did twice but i will recheck again on monday. I know the 08 map is different then the 09+ one but i dont see why it wouldnt work wired in correctly but i just got a 09+ map with pigtail that i will wire in and see what happens. If anyone has any more ideas let me know please
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Old Aug 12, 2017 | 10:49 PM
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not only are they wired differently, they also have different scaling in the ecu. Steve
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Old Aug 12, 2017 | 11:09 PM
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Yea i know but i already copied the values to the tune from an 08 file so that shouldn't be the problem.
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Old Aug 15, 2017 | 12:02 AM
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Ok found my problem. Simple thing but hard to find. Somehow the gasket in the ECM connector wasn't seated right and prevented the connector from going in all the way and didn't make connection. Weird is that only the map wasn't working and everything else did but glad i found it. Thanks for the advice though.
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