I have a 06 3500 5.9 automatic 4x4 Laramine QC. I keep geting the code P0581. I clear it and it keeps coming back. My cruise works sometimes and othertimes it doesnt. The cruise light on the dash comes on when it works and doesnt come on when it doesnt work. When it does work I will be going down the road and all of a sudden the cruise just kicks out and the cruise light shuts off. Does anyone out there know whats happening? I have brought it to my mechanic numerous times and he clears the code and he cant seem to find whats causing it. When have no clue thats why I am coming to you.

 

P0581-HIGH VOLTAGE DETECTED AT THE SPEED CONTROL SWITCH

Well it is probably a wiring harness issue. That is the first thing the manual lists as diagnostics.

I would check all of the Juice fuse taps first or remove it altogether to see if it is part of the issue.

Unfortunately the diagnostics covers many modules and connections.

Probable Causes:

S/C WIRING HARNESS OBSERVABLE PROBLEM
CLOCKSPRING SIGNAL/GROUND CIRCUIT OPEN
SPEED CONTROL ON/OFF SWITCH
S/C SWITCH SIGNAL CKT SHORTED TO VOLTAGE
S/C SWITCH SIGNAL CIRCUIT OPEN ECM TO CLOCK SPRING
S/C SWITCH SIGNAL CIRCUIT OPEN CLOCKSPRING TO S/C SWITCH
S/C SWITCH GROUND CIRCUIT OPEN CLOCKSPRING TO S/C SWITCH
S/C SWITCH GROUND CIRCUIT OPEN ECM TO CLOCKSPRING
ECM