High idle?

2017 FORD F-250
90,000 MILES • 6.7L • V8 • 4WD • AUTOMATIC
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MUKHIDA1
  • MEMBER
  • 1 POST
when truck is on for few minutes i goes on very high RPMs, when you hit brake or gas just a touch it comes back to normal and after minute or so it goes back again on high.
Sep 19, 2023 at 10:51 AM
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DGADEMSEY
  • CERTIFIED EXPERT
  • 15 POSTS
Hello,

The reason your truck is doing this is very simple. With the exhaust after-treatment systems on diesel vehicles the DPF (diesel particulate filter) and the DOC (diesel oxidation catalyst) will plug due to soot loading. The computer sees the idle time and increases engine speed to heat the filters up and burn out the pollutants. When the computer sees that the throttle pedal or brake pedal is depressed it shuts the high idle function off.

Dustin
Sep 19, 2023 at 1:38 PM