Shifting into neutral
Hi everyone, I'm fairly certain this is "normal," but since diesel trucks are new to me, I figured I'd ask. I have a 2008 Chevy Silverado 3500 Duramax w/ the 6-speed Allison transmission. Las...
Forum Discussion
I want to clarify a few misnomers here.
For Ben this 1st one applies to your California Law.
1. All Ford Vehicles shift into neutral when they sense the vehicle speed versus throttle input while monitoring the BOO switch. If the PCM does not detect that you are applying the brake, and the TOW/HAUL mode is inactive, the PCM will shift the transmission and "coast" down hill all on it's own. This is designed as a way to save fuel. Anyone who drives a ford truck or car can tell you the feeling of the vehicle "speeding up on it's own" when their foot is off the gas.
2. The fact that the IPC and the Vehicle speed sensor on the truck is detecting movement in relation to the Fuel pressure, when shifting into neutral the PCM won't compensate right away. This is what one of the other posters were saying. The PCM is thinking it needs is off on the RPM input and increases fuel pressure. Odd and backwards of a "engine braking situation"
3. Any person who lives in a location that has snow, ice or black ice knows, to stop safely you need to shift into neutral and eliminate engine braking. The PCM's in most cars automatically do not engine brake any longer, unless you put your foot on the brake, at which point the transmission will automatically down shift at certain speeds. This can be dangerous in a RWD vehicle, it is best to shift into neutral and apply light brake pressure to slow the vehicle.
For Ben this 1st one applies to your California Law.
1. All Ford Vehicles shift into neutral when they sense the vehicle speed versus throttle input while monitoring the BOO switch. If the PCM does not detect that you are applying the brake, and the TOW/HAUL mode is inactive, the PCM will shift the transmission and "coast" down hill all on it's own. This is designed as a way to save fuel. Anyone who drives a ford truck or car can tell you the feeling of the vehicle "speeding up on it's own" when their foot is off the gas.
2. The fact that the IPC and the Vehicle speed sensor on the truck is detecting movement in relation to the Fuel pressure, when shifting into neutral the PCM won't compensate right away. This is what one of the other posters were saying. The PCM is thinking it needs is off on the RPM input and increases fuel pressure. Odd and backwards of a "engine braking situation"
3. Any person who lives in a location that has snow, ice or black ice knows, to stop safely you need to shift into neutral and eliminate engine braking. The PCM's in most cars automatically do not engine brake any longer, unless you put your foot on the brake, at which point the transmission will automatically down shift at certain speeds. This can be dangerous in a RWD vehicle, it is best to shift into neutral and apply light brake pressure to slow the vehicle.
