Engine/Transmission (1998.5 - 2002) Factory High Idle is puzzling, but works now.

[JCyrbok]

I have had the ECM High Idle/3cylinder function activated twice by the dealer. First time never worked. Also thought that the second time that it didnt work either. Kinda gave up on it as I have been well with in the parameters, 100 times, for it to kick in.



The other day I came out of work after changing and hitting the remote start and truck was idleing at 1200rpm !!! Did it again this moring!



Prior to this only thing that I had changed was adding a DTT Noise Filter to take care of trans shift problems(which it did).



My thoughts are that the ECM was previously "seeing" the APPS as "not at idle" so the High Idle would not kick in even though the parameters were met. Now with the noise filter the ECM is seeing the APPS signal "clean" and letting the high idle kick in.



Sound good/possible? Only thing that I can think of after 5 years and no workie on the high idle.



Just an idea,

J-

 

[Turbo Tim 1]

I know with mine it has to be 20 or below to do the high idle and the truck needs to be off for 10-12 hours at that temperature in order to get it to high idle.

 

[JCyrbok]

Yup temp and time are right ( it was in the low 20's both times and I work 12hrs).



But there has been times when it was WAY lower than 20 and longer than 12hrs and it didnt work. Go figure, as long as it is working now, what ever fixed it!



J-