I did a search looking for the answer to my question but could not find a definite one. I have a new, 08 Tundra 5.7 (2WD) and was driving in the mountains this weekend. I noticed that when going down a fairly steep grade, the engine seemed to stick or rev slightly when I took my foot off of the gas. After sometime, it would eventually downshift, though not always when I put my foot on the brake. It was not in the Tow/Haul mode. I read some posts about the Shift-Logic system and how it will downshift if you hit the brakes while going downhill. I could not find anything about the engine rpms staying the same or slightly increasing when your foot was taken off of the gas. Is this normal?
The reason the rpm is staying or even revving up a little higher is because the tranny is either holding the gear you are in or downshifting depending on how steep the grade is. When it downshifts the rpm's will rise thus helping you stay at a safe speed with engine braking. The higher the rpm is the more engine braking can occur.
...To answer your question...Yes it is normal...
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DCSB SR5 2WD
-THE MONSTROUS 5.7, 6SPD AUTO, TOW PACKAGE W/4.30 GEARS BABY!, STEBEL 300HZ TRUCK HORN+2 FACTORY HORNS, K&N 77 SERIES INTAKE, TOYTEC 3" LIFT, DEBADGED SYLVANIA H9 LOW BEAM MOD (2100 LUMENS), HIR1 HI BEAM MOD (2350 LUMENS), SILVERSTAR EURO SIGNALS, BLACK HEADLIGHT MOD, BLACK BADGE, JBL 440W SYSTEM W/ NAV W/ BACKUP CAM, SONAR, ESCORT PASSPORT 8500 X50 RADAR, MOTO METAL 951 18" RIMS, MAGNAFLOW 14" 2 IN/2 OUT CATBACK EXHAUST -SYSTEM WITH 4" MAGNAFLOW TIPS, BFG TA KO 285/65/18's!!(32.7"), PIONEER PREMIER SPEAKERS, 2 PREMIER 10" SUBS, 2 KICKER AMPS!!!
"As I walk through the valley of the shadow of death I have no fear because I am the meanest motherf*cker in the valley"
If you're using cruise control, it'll definitely downshift and keep it within 5 MPH of your set speed. The more you let the computer handle things in this truck, the nicer it performs.
Sorry, I should have said that I was not using a cruise control.
What you were saying is normal even when not using cruise control. This truck is smart. It knows when you are going down a steep hill and starting to accelerate quickly so it downshifts on its own. Even in regular driving without cruise control. Even if you are in traffic and come to a really quick emergency stop it knows that and downshifts more quickly to help you slow down.
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DCSB SR5 2WD
-THE MONSTROUS 5.7, 6SPD AUTO, TOW PACKAGE W/4.30 GEARS BABY!, STEBEL 300HZ TRUCK HORN+2 FACTORY HORNS, K&N 77 SERIES INTAKE, TOYTEC 3" LIFT, DEBADGED SYLVANIA H9 LOW BEAM MOD (2100 LUMENS), HIR1 HI BEAM MOD (2350 LUMENS), SILVERSTAR EURO SIGNALS, BLACK HEADLIGHT MOD, BLACK BADGE, JBL 440W SYSTEM W/ NAV W/ BACKUP CAM, SONAR, ESCORT PASSPORT 8500 X50 RADAR, MOTO METAL 951 18" RIMS, MAGNAFLOW 14" 2 IN/2 OUT CATBACK EXHAUST -SYSTEM WITH 4" MAGNAFLOW TIPS, BFG TA KO 285/65/18's!!(32.7"), PIONEER PREMIER SPEAKERS, 2 PREMIER 10" SUBS, 2 KICKER AMPS!!!
"As I walk through the valley of the shadow of death I have no fear because I am the meanest motherf*cker in the valley"
It's not the downshifting that bothers me so much. It's the fact that when I let off of the gas, it does not begin to decelerate. The engine feels like it hangs where it is and there is no change in the rpm. It takes several seconds, perhaps 5, to begin to slow. In my previous vehicle, a 4Runner, it would immediately decelerate when you let off of the gas going down the hill. It just feels like the engine gets momentarily stuck.
It's not the downshifting that bothers me so much. It's the fact that when I let off of the gas, it does not begin to decelerate. The engine feels like it hangs where it is and there is no change in the rpm. It takes several seconds, perhaps 5, to begin to slow. In my previous vehicle, a 4Runner, it would immediately decelerate when you let off of the gas going down the hill. It just feels like the engine gets momentarily stuck.
Haha now that you are getting more clear about this situation it does not sound so normal to me. If its hanging up for a few seconds you might want to get that checked out. Being an '08 Tundra I'm sure they would be happy to look at it at your dealer.
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DCSB SR5 2WD
-THE MONSTROUS 5.7, 6SPD AUTO, TOW PACKAGE W/4.30 GEARS BABY!, STEBEL 300HZ TRUCK HORN+2 FACTORY HORNS, K&N 77 SERIES INTAKE, TOYTEC 3" LIFT, DEBADGED SYLVANIA H9 LOW BEAM MOD (2100 LUMENS), HIR1 HI BEAM MOD (2350 LUMENS), SILVERSTAR EURO SIGNALS, BLACK HEADLIGHT MOD, BLACK BADGE, JBL 440W SYSTEM W/ NAV W/ BACKUP CAM, SONAR, ESCORT PASSPORT 8500 X50 RADAR, MOTO METAL 951 18" RIMS, MAGNAFLOW 14" 2 IN/2 OUT CATBACK EXHAUST -SYSTEM WITH 4" MAGNAFLOW TIPS, BFG TA KO 285/65/18's!!(32.7"), PIONEER PREMIER SPEAKERS, 2 PREMIER 10" SUBS, 2 KICKER AMPS!!!
"As I walk through the valley of the shadow of death I have no fear because I am the meanest motherf*cker in the valley"
mine does it as well acording to the scan guage the gph and the instant mpg go though the roof on any down grade the injectors stop fireing fuel (saving gas) the reasion it doesnt slow i believe is be cause of the vvt (valve timing the pcm controls)
its hard for me to explain but my vw does the same thing. and for the most part has the same vvt but on the exhuast not the intake. its also a manual and it does not do engine brakeing like any other car/truck i have ever had.
Sounds normal to me. How fast do you expect it to decelerate on a downhill grade , especially in 6th gear? It takes a few seconds for the ECM to know you are going downhill and then to downshift to slow you down via engine braking. I dont see a problem here.
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07 Tundra DC TRD 4WD 5.7L Desert Mica
Tundrakh, my 08 does the same thing. I took it in and they said, "that's what it's designed to do." Just like the bed is "designed" to flop around like it's made of plastic and the cd player is "designed" to work only when you hit the dash with your hand. But hey, at least it's fast.
Thanks folks. Guess I'm just used to a car decelerating immediately when I remove my foot from the accelerator. This just feels like it hangs there for a few seconds. Even a friend riding with me noticed. But......if it's normal, it's normal.
It's normal...flex lock-up, fuel cut mode, engine braking when you touch the fat pedal or when cruise is set on downhills, and downshifts when you hit the magic speed while slowing.
There's a white paper on the 6 speed floating around here somewhere???
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mine will not downshift going downhill when the brakes are applied IF i drive in the manual shift position. I was so glas i discovered this because it was really getting on my nerves.
Transmission rev/shift going downhill?
Linear Mode
