going to see if this helps me, I've got a 1997 GMC with a 2000 4.8l swap. I've driven it a total of two miles....no speedo or trip working. The ABS is on as well. Now that being said, the speedo sensor was "Y'd" to both the OBS ecu and the NBS ecu. Supposedly, the signal was split in order for new ecu to run shifting duties and the old ecu to deal with gauges.

Any suggestions