Idle and shifing ???

biochemist · January 15, 2005

Hi guys, couple of quesitons. Do your trucks shift a bit differently when cold (a recent string leads me to think so), mine shifts a bit harder (1-2 shift) when cold outside...until it warms a bit. It also seems to like to be driven a bit harder than I usually drive, in other words it shifts harder from 1-2 if I am putting around than if I takeoff more briskly...I guess this is the transmission learning and trying to second guess what I do? Most all of the time it is pefectly smooth....cannot even tell it shifts really just here and there I notice it will be a bit harsher depending on temp and my driving style....

Idle, mine usually idles ~500 when in P and when I stop a a sign...but if you put it in nuetral when driving it fluctualtes from 200-500 sometimes. (this is kind of a dumb thing to notice I know ) I assume this is just the truck trying to get as good MPG as possible while coasting. I was just trying to listen to tire noise (trying to decide about ST to REVO replacement) and I noticed the RPM will dip when coasting in N ~30-50 MPH (lights will dim a bit also).....not a big deal, idles fine in P and when I stop, just wanted to know if anyone noticed while traveling at high speeds the RPMS will dip and fluctuate? let me know what you think,

budhayes3 · January 15, 2005

The shift concern is normal, but I've never put me vehicle in neutral while driving and observed it before...I would think this might confuse the PCM and is probably not recommended practice. I don't think that the PCM should be seeing a speed signal and shift select signal of N at the same time.

biochemist · January 15, 2005

The shift concern is normal, but I've never put me vehicle in neutral while driving and observed it before...I would think this might confuse the PCM and is probably not recommended practice. I don't think that the PCM should be seeing a speed signal and shift select signal of N at the same time.

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Right on with that I just wanted the noise level as low as possible to observe the tire noise...never thought it would hurt anything, probably would not but I will refrain from this practice anyway. I figured both questions were normal, but hey this place is great for questions like this....Thanks for the reply