Downshifting when?

[supreme_style21]

I don't even know how to title this one and not sound like a bigger idiot. My '97 Olds likes to downshift/drop out of OD when I've got the cruise set when the car is going down even the slightest incline... the rpm's raise about 100... once the road levels out, it drops back into OD. I've never had my old cars do this. Is it normal or am I just paranoid?

[19Cutlass94]

Its normal.

[Cam'ron]

it is the cars attempt to maintain your set cruise speed. normal dont worry my 03 does the same thing

[19Cutlass94]

When your going down a hill, in cruise, the car kicks out of OD and goes into neutral to maintain speed. Also heps in the MPG depo. Then when you need to speed up, it gets back on the gas. The electronic cruise holds it to about +/- 1mph from the speed you set the cruise on.

[supreme_style21]

Alright thats what I was assuming... I just had never had a previous car do it, so I wasn't entirely sure.

[Robby1870]

Mine only does that when Im going down a very steep hill. I'll see the DIC say 99mpg and I know its kicked out, but otherwise it stays in. I guess thats a non-E tranny for ya (which I much prefer).

[Calvin]

I am pretty sure it is not popping out of OD, I am pretty sure it is just unlocking the TCC, as I think in the code the TCC usually unlocks when the throttle is below 5% or so open in most .bins. Your throttle would only be open very slightly when coasting down hill even with cruise on and may be approaching that threshold. 100RPM sounds more like TCC than gearshift which should result in something more like a 20% change in RPM

 

Kurt

 

[Robby1870]

I am pretty sure it is not popping out of OD, I am pretty sure it is just unlocking the TCC, as I think in the code the TCC usually unlocks when the throttle is below 5% or so open in most .bins. Your throttle would only be open very slightly when coasting down hill even with cruise on and may be approaching that threshold. 100RPM sounds more like TCC than gearshift which should result in something more like a 20% change in RPM

 

Kurt

 

 

yeah, its definitley kicking the TCC off.

[supreme_style21]

ok thanks.

[SigEpCutlass]

I don't even know how to title this one and not sound like a bigger idiot. My '97 Olds likes to downshift/drop out of OD when I've got the cruise set when the car is going down even the slightest incline... the rpm's raise about 100... once the road levels out, it drops back into OD. I've never had my old cars do this. Is it normal or am I just paranoid?

 

Mine only does it when it's a more significant incline that it's trying to keep its speed going up if I'm traveling less than 70. Otherwise, it doesn't usually downshift. I don't think it's a serious problem, so don't worry.