I noticed that my rpm at idle has gone from 850 to just a little over 900. This is a constant thing even when warm.Does this indicate a problem? What's the cause and is there a fix? No codes. Thanks for any help.

What's your engine temp like? The colder the engine temp the highier the idle so if your thermostat is going south and staying cold the idle speed will rise.

I have kept note of the engine temp, runs normal at 190 and I don't notice a difference in rpm. Could this be a throttle control sensor issue? I don't think there is any adjustment for the throttle on this model. Don't know for sure.

No way to manually adjust idle on our trucks, but as Mike said, watch the temp gauge.

I have kept note of the engine temp, runs normal at 190 and I don't notice a difference in rpm. Could this be a throttle control sensor issue? I don't think there is any adjustment for the throttle on this model. Don't know for sure.

No way to manually adjust idle on our trucks, but as Mike said, watch the temp gauge.

He's correct. There is no adjustment for idle on our trucks. The APPS sensor when its at idle the voltage is not used.

So when switch one is grounded the ECM uses its internal software govern idle speeds based off of engine coolant temperature.

When my apps senser was going out on me, I did have some idle issues. It was usually only after I had cruised for more than 10 minutes or so, but the idle wouldnt come back down below 900-1000 rpms. You might reset the apps just to see if it helps at all.