[consultIII]

you will be disconnecting the high signal wire at each end. So, if its good there should be no source to grd and the meter will read OL.

You can test at either end (which ever is easiest to access). black ohmmeter lead to chassis grd and red lead to the purple/white wire. Use a t-pin (available at sewing store...quilting tpin) and probe from the back of the connector if the terminials are small; you don't want to spread the female connectors and cause a pin fit problem.

If all is ok and the pin fit and connectors at the ecm are ok...very well could be pcm time. a new pcm must be programmed by the dealer. You could also get a used pcm from the wrecker and have it programmed to your vin. See if your dealer would do that and if its ok. a used pcm may or may not start the car due to the theft deterrant system.