Fast idle behavior
Postmaster
Joined: Dec 2003
Posts: 4,196
Likes: 10
From: Arizona
Originally Posted by NorCalBusa
I plan on hooking mine up...was wondering the details- is it smart? Disengage when you shift, tap the brake, open the door, won't turn on underway, etc.?
http://www.ford-trucks.com/forums/40...-switches.html
There are no ill effects from hooking this up, it has been used for many years on ambulances, tow trucks, boom trucks etc. It will only engage when all these parameters are met:
All the following are required to enable high idle:
Parking brake applied.
Foot off of service brake.
Vehicle in PARK (automatic trans.)
Foot off of clutch (manual trans.)
Foot off of accelerator pedal
Vehicle speed is 0 mph (stationary)
Brake lights functional
Engine at a stable base idle speed
Originally Posted by msgtg
As soon as you touch the brake, it idles down. Never heard of it idling down by opening a door. FYI, mine only goes into this mode in cold weather.
What you are experiencing is a normal program in the PCM of all PSD SD that cause the engine speed to idle up when the engine is cold, to help reach operating temperature sooner. When the truck is warm this strategy does not come into play. The "High Idle Mod" is used at any engine temperature and is manually selected. The sequence is used to prevent wet stacking and either maintain the battery charge or power the PTO output on the transmission.
Hope this helps
