PCM Bench Harness Wiring diagrams

[Blacky]

Can you have a harness connector directly wired into a db9? This would bypass the OBDII connector all together.

Yes - good idea, I will add that into the diagram.
Paul

Document has been updated with 9-pin D-connectors.

Regards
Paul

[BigTex]

In the past, every tune I made with LS1edit on my truck needed a benchtop harness. I made my own using a spare wire harness a couple of years back. I skipped the OBD2 connection and went right to DB9 which worked fine.


The two PCM connectors (blue and red) are keyed so they only fit in one way on the PCM. Typically you use the blue one to build the harness and toss out the red one. If you cut off the plastic keys from the red one it will fit in either side of the PCM, so you can use that connector to build a second harness. Just remember which side its supposed to go in.


When bench tuning my truck, I've always left the PCM installed with the second harness connector attached. I just remove the blue connector and get power from the vehicles battery.

[kewlklown]

Yes, where can we purchase the pcm connectors from...?

I know this an old thread, but Obd2 connectors available at mouser.com

[joecar]

I know this an old thread, but Obd2 connectors available at mouser.com

Yes, we have found a bunch of various connectors at mouser.com.