Been tinkering with this stupid thing for over a month now. Was driving home from work, turned on my road and the speedometer quit, cel light came on and d4 started blinking. Having been through this before, I checked my vss, plugs, wiring, swapped my ecm, tcm and cluster. Still wouldn't work. Took the cluster apart and swapped speedos thinking maybe a 4 door cluster board was different than 2 door. Still nothing. Checked voltage at the vss plug, made sure the signal wire was intact to the cluster, checked for ground at the sensor plug and changed main shaft sensor too. All this and still no speed. Any thoughts? The engine, trans and wiring are from a 96 model OBD1 EX 4 door. Everything worked perfectly after the engine swap and really haven't had any new problems other than this.