Idle nearly 1000rpm's by itself?

[PwrStrkTrucker]

Started my truck the other morning, it was cold...about 35 degrees outside. Walked away for a few minutes (to let the truck warm up) and came back 3-5 minutes later, trucks rpm's were about 1000 at idle and it happened on its own. When i hit the brake pedal it went to normal idle. This is similar to what my Peterbilt does. Is this normal for a PSD? Auto idle up when cold?

[MR.BIGHILLBILLY74]

Yes this is normal! There is nothing wrong with your truck! It's just like the big rigs. My truck does it every morning whether it is plugged in or not! I've also done the high idle mod on mine and can control this by flipping a switch.

[PwrStrkTrucker]

Well a bit different. On my semi, I have to manually up the rpm's by the use of the cruise control switches, basically a throttle control, but manually. On the SD it went up on its own all the way to 1000rpms. It has not happened since. Is this only when its really cold? The manual says nothing! I always let it warm up for a bit but that was weird, just shot up on its own and went down after I hit the brake pedal. Anybody else have this occurance?

[MR.BIGHILLBILLY74]

Yes this is perfectly normal! You do not have to touch anything and it will do it! There is a sensor that tells the computer when the truck is cold (below like 40?) and it will bump up the rpm's to 1000 to 1200 to help the truck warm up faster. Once the truck has reached operating temps it will drop back down to normal or if you hit the brake or go pedal it will also drop the rpm's back down.

[stump0331]

yeah all our trucks do it, perfectly normal