Greetings how do I pull codes from a 94 E350 van with the three/four wheel ABS? I do have a code reader but only will read engine codes as far I know from the connector under the hood? There is a loose round connector under the van right by the ABS computer that looks like ABS connector I have seen in photos.

The problem I am having is ABS light is on from the moment I turn the key to Acc so I assume it's hard fault something not related the wheel sensors, and the trans is shifting hard, I replaced my rear pumpkin ABS sensor already.