Volvo Repair: 311-Vehicle speed signal missing, engine wiring harness, coolant temp

Question
Roger, Thanks you are the man, I found the speed sensor on trans wires melted together, replaced sensor car ran fine for a while.  after a hour-45 min. the motor gets a miss and shakes with on A/C (maybe not relevant)and I keep getting code 311.  Im lost on how speedometer sending unit is connected to the fuel injection system, the speed signal unit is mounted in the diff and car is not equipped with ABS.  The miss in the engine occurred in park as I was recharging the A/C on the military base at the autocraft shop. thoughts?  Replaced; fuel pump(in tank),swap fuel pump relay, eng coolant temp sensor, eng RPM sensor mounted on front top of transmission.

Answer
Pat, There is no relevance on that.  are you sure its not a 113 code?  If it is, then the ECU is the culprit.  It may be an engine wiring harness issue also.   You are chasing a ghost.  Its one of those things that I would have to look at in person to determine what the heck is going on.  Roger