CV713, AMI-370: High Idle, Throttle Position Sensor , Intermittent Cruise Control

[Timber_Mack]

I am chasing an intermittent electronic issue in my 2006 Granite, AMI-370.  Have replaced the gas pedal ($500) and asked the dealer to calibrate, though not sure what they actually did.  There was an initial improvement in drivability, though still some hiccups.   Upon startup,  the truck idle speed will often begin to drift up from 650 to 1000+ rpm.  I can turn on the ECM control for the PTO boom which takes over engine and brings idle back down, usually.  However, when driving on the road, the only way to bring the idle down is to hold the 'gas' pedal down slightly.

Often the truck will bog down while driving.  Sometimes,  cruise control will perk it back up to full power, using the accelerate button.  However, Cruise Control will intermittently stop working at which point, the truck bogs down to a crawl.

I have been reading various topics on these forums and am checking ground connections, clutch pedal switch, relay connections, but am still looking for causes.

The truck is throwing a 5-1 code, when cruise control is operating.

Problems seem to be more persistent in wet conditions.

Any suggestions would be greatly appreciated.

Timber...:-)