DANGEROUS THROTTLE CONDITION

NOTE: The following condition is known to exist on SOME 1997 and 1998 models, and is NOT limited to Discovery coaches.   You may want to check your coach also

Most of you know that you can idle your engine at a "fast idle" that is approx 200 rpm higher than normal idle by tapping the cruise control button twice with the cruise control on.   But, did you also know that this deactivates the throttle?

Simply said, if you accidently activate your fast idle while driving, your throttle is now INACTIVE! The solution is to immediately turn off the cruise control or hit the brake, but how many of you would immediatly think of that? Especially hitting the brake as you are likely trying to accelerate, not stop.

The engine, as delivered by Cummins, has the engine parameters set for a MANUAL transmission.   Changes in the engine parameter settings are the responsibility of the engine installer, according to Cummins, The parameter that we are interested in here is the Fast Idle/Power Take Off upper speed limit.   Cummins sets this to 6 mph, and when you activate the fast idle, your coach will travel at no more than 6 mph no matter how hard you press down on the accelerator.   If you coach has this problem, you may want to have Cummins reset this parameter to 0 mph, or have them activate the "Throttle Override in PTO" parameter, which will completely eliminate this problem and still allow you to use the fast idle feature for engine warm-up.
-Thanks to Dennis Uphill, via the Internet