So I go to get my truck tuned. (truck wasnt idling and running like *** esp under load). So we logged it and the map wasn't reading at all.

So we tried another sensor we had on hand that was working tried that no luck.

So next step was to test the wires.

A- Orange/Blk (Low Reference / MAP Ground) C1-54

B- Light Green (Map Sensor Signal) C2-32

C- Gray (5v Reference for Map Sensor) C1-48

The low reference checked out

5v Reference was perfect

Jumped the signal wire from 5v and the signal wire read 5v and maxed the map signal readings as it should.

So why does my map sensor not read.

I want to say it read properly a few times on key-on. (not 100% sure)

but nothing reads anymore could my pcm be going bad or where should i look? Bad/failing pcm ground?

Made a test lead directly from the Negative battery terminal to the pcm grounds just to be positive it had a perfect ground and that didnt help anything.

I'm seriously lost.

any help appreciated.

when i first wired the motor up the motor fired and drove but not perfect. but really wont run or idle now. idles a smidge better when hot but still doesn't run worth a crap.

 

Its possible the connector sucks. Ive had pins get pushed back in the connector so they dont make good contact with the sensor. I recommend replacing the connector by soldering on a new one. Chances are the actual MAP sensor is fine.

 

I've had problems with mine by not using a factory GM sensor. Running the 2 bar OS on my truck and trying to use anything other than a GM 2 bar sensor and the truck just doesn't like it. But if both sensors you've tried were GM sensors it kinda rules out that possibility.

 

okay so today i tried to see if it was the connector so i took all the wires out of it and set the wires in there manually. i noticed that as soon as i put the ground in there i lost volt readings. what does this mean???

 

a buddy of mine thinks if it isnt the sensor its the pcm???