Map sensor not reading
08-12-2017, 05:10 PM
#1
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.
08-12-2017, 09:40 PM
#4
I checked for the pins on the ecm connector and compared to a pinout for a 2009 and they were the same and the pictures you posted prove that. And i knew that the connectors were different on the map but i double checked that and rewired it but still didnt work. I just got a 09+ map with pigtail and i will wire that in on monday and see if i get different results but i dont see why a 08 map wouldnt work. If anyone has any more ideas to try let me know though.
08-15-2017, 12:02 AM
#5
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.