John Boy

iTrader: (3)

Can someone clue me in on the purpose of two grounds going to the MAF on the 165 ECM. One is labeled analog ground and that has me confused. I'm working on a TPI swap into a jeep and I'm getting nowhere fast with my tuning. Now matter what changes I made in my MAF tables the airflow is off. I sent the MAF off to be rebuilt but I'm starting to think they messed up. It's under warranty but I want to be sure before I send it back.

Here is the thread from the DIY PROM board where I started trouble shooting the problem. https://www.thirdgen.org/forums/diy-...swap-help.html

Now the problem is the output (green) wire reads ~5 volts at idle. Which the ECM sees as high or a raw input of 254. This is the problem.

So before I send the sensor back for warranty work I was wondering about the analog ground, how does that work and how is it different. I know it goes back to the ECM where as the system ground I think I have going to the firewall or back of the head, don't remember.

Anyway is there anything that could be wrong with the analog ground that would make the sensor read wrong? That's my main question, since I believe I have everything else correct. Thanks if you read my whole rambling post.