E38 no OBD2 connection, engine runs normal

[Squintah81]

I have a 2012 Camaro with an individual motorsports harness with the standalone E38. Engine runs and everything works fine. I have double checked the wires with a multimeter and I double checked positions, everything is where it should be.

Any suggestions?


Thanks in advance ✌🏼

[gtstorey]

So, what are you trying to do?

And should probably be posting in GM v8 Gen4 section.

[Squintah81]

I just want to get a connection.

Info log says "unable to detect the vehicles diagnostic protocol"

[gtstorey]

So it has a OBD port but is unable to read then. Have you confirmed all the power connections to the ECM? Does the wiring harness have the second 120ohm resistor? Is there anything else that might be broadcasting on the data wires?

This is 99% a wiring issue.

[Squintah81]

I hope so.

It's a stand alone ECU, no other controllers, because of TH400 transmission and mechanical fuel pressure regulator.

I have routed the can wires directly from the ECU to the DLC. And it worked like this before. I just have redonde the wiring on a new board.

[gtstorey]

Not much more that can be done remotely. This is a hands on problem that can only be speculated on. Basically, the information we have is "it's broke". So either your wiring is screwed up, your ECM is screwed up or your HPT is screwed up. Have you tried using anything else to communicate with the ECM?

[Squintah81]

This is the info read. I've connected the CAN wires flying from ECU connector to the DLC to test if it's in the wiring. No change. I've sprayed also a little contact spray, just in case.

OBD2-no-connection-2012-Camaro-E38-ECU.JPG

[gtstorey]

This is the info read. I've connected the CAN wires flying from ECU connector to the DLC to test if it's in the wiring. No change. I've sprayed also a little contact spray, just in case.

OBD2-no-connection-2012-Camaro-E38-ECU.JPG

I don't think any of that says anything as far as reading a vehicle. That is just the VCM program info.

Only other thing to do is open a support ticket. Or post this in the GM Gen4 V8 section to see if anyone has any ideas. I would try connecting a different scanner to see if it connects. Even the loaner tool from Autozone if nothing else.

[gtstorey]

I will add that saying you "sprayed contact cleaner, just in case" sounds like your electrical skills are lacking. But here are some checks that you can do to test the high speed network.

https://resources.aeswave.com/ATG-05...%20may%20occur.