Stuck in V-8 mode?

Debra in Cali · July 9, 2015

This past weekend, twice when I was going down hill it wouldn't switch over to V-4 mode. The first time it did it after a mile or two I pulled over, put it into neutral and then back into drive. That seemed to fix the problem because it immediately switched over to V-4 once I got moving again. Then the second time was a day or two later. I tried the put it into neutral trick and that did not work. I then tried the turn off the engine and restart it to see if that would reset the computer. That didn't even work. Finally, it just switched over on its own, but it took it around 20 miles of up and down before it kicked back in again. I am going to talk to the dealer tomorrow.

Anybody else have this issue?

MMC · July 9, 2015

After ten minutes it will always revert to V8 for one minute then if the system requirements are met it will return to V4.

tnchevy · July 9, 2015

There is a pretty long down hill grade I drive on a 4 lane before I turn off to get to my house. My truck always stays in V8 mode on that long steady down hill grade even though I hardly have the gas pedal pushed. As soon as I turn onto the county road and start to speed up it goes into V4 mode. I don't know what it is about this particular hill but it likes to stay in V8 mode on it but other downhill grades it will go into V4.

irish4life8911 · July 9, 2015

Have you put different size tires/ different weight tires? Level kit? Different tire weights will prevent v4

MikeNH · July 9, 2015

Are you in drive or one of the manual gears?

Dunc · July 9, 2015

There is a pretty long down hill grade I drive on a 4 lane before I turn off to get to my house. My truck always stays in V8 mode on that long steady down hill grade even though I hardly have the gas pedal pushed. As soon as I turn onto the county road and start to speed up it goes into V4 mode. I don't know what it is about this particular hill but it likes to stay in V8 mode on it but other downhill grades it will go into V4.

Will leaving all 8 firing increase engine breaking? I would think so, but don't know. Perhaps the truck leaves all 8 on to try to satisfy some software logic about engine braking.

Debra in Cali · July 9, 2015

Engine braking was not on. I have been driving those roads all the time and it has dropped to V-4 all the other times.

20L8TSierra24 · July 9, 2015

I drive mine around in m5 just so it don't go into v4.

Silverado Steve · July 9, 2015

Whats youre average mpg's? If they dropped considerably, then there would be some cause for concern. My truck is similiar in that it doesnt always drop to V4 going down hill, im sure some of it is for engine braking and the other is the ECM wants to be in V8 mode in case of a sudden incline. My instant mpgs shoots up to 99 mpg, so the engine is just idling, to which these trucks always idle in V8 mode.

DirtyMarcus · July 9, 2015

I can get my truck to go into V4 by letting off the gas for a second. It usually switches pretty quick then I can keep in V4 by controlling the throttle.

Sooperdave · July 9, 2015

Just have to let off the throttle then just tip it. It should click over. However I have noticed when going downhill, it will not go in to V4. Once you figure out the system it works great!

Debra in Cali · July 9, 2015

Have you put different size tires/ different weight tires? Level kit? Different tire weights will prevent v4

Nope, no modifications.

Debra in Cali · July 9, 2015

I can get my truck to go into V4 by letting off the gas for a second. It usually switches pretty quick then I can keep in V4 by controlling the throttle.

I wasn't on the gas at all during both of these incidents. I was coasting down hill.