NEED HELP!! OBD2 Not Connecting and Does have Power

[viperbmw69]

I was able to connect to the OBD2 port yesterday and everything was working fine. I unplugged the ECM to fix a speed sensor wire and plugged it back in and now I get no connection when I plug in my OBD2 scanner. I see Grounds on both grounds on the DLC port I have 12v on red power. I have 2.5ish on Brown/BLK and 2.5ish on Brown wire This is all with the key in the On position.

I tested my OBD2 on another car it its working fine.

I get 120 OHMs resistance from the EPS unit and I get 120ohms resistance from the ECU. I checked the wires and all the wires are showing good continuity for the GMLAN and power.

STILL not connecting

 

[Gtstorey]

Check for 60ohms from pin 6 to pin 14 on the DLC/OBD2.
SECTION ‘X’ CONTENTS (aeswave.com)

It's probably a bad connection at the ECM connector you disconnected.

 

[viperbmw69]

I get 120ohms on the TN and TN/BLK wires at the Connector to the BCM coming from the ECM. So I am not sure how that could be...

 

[Gtstorey]

Not sure about what? The 60 Ohms?

 

[Joebob]

The EPS and the ECU each have a 120 Ohm resister. if you check the resistance at the OBD2 port and read 120 Ohms, one of the wires to either the EPS or the ECU are not connected. I fully connected system will read 60 Ohm resistance.

How to test a CAN bus network with a meter - YouTube

 

[viperbmw69]

Update:
It’s fixed. Turned out to be a loose J2 connection on the BCM I found it by wiggling it. Cleaned and bent the plastic tabs to hold solid. Thanks everyone for the fire drill.