FCA Programers not very bright

[bm02tj]

If you live on top of a hill you have to run your truck for 3 to 4 minutes to make the computer happy
If not the computer program adds fuel going down hill so when you gear down the RPM goes up
For a test I tried cruise control
Started down 9% grade set cruise at 51KM/32MPH
To control speed it shifted down until I was at 4800RPM
showing 14Ltrs per 10Km or 20Mpg
1/2 way down hill computer was happy and backed off the truck slowed and shifted up a gear

If any one else lives on a hill please try this then complain so maybe they will fix there lack of understanding how trucks work and saving your brakes
Thanks Bruce

 

[Tach_tech]

So what happens if you let it run for 3-4 minutes before going down the hill? What do you want the truck to do? Was it gaining speed downhill or was it maintaining the set cruise point?

It’s pretty normal for the trans to downshift going down a hill as it try’s to maintain speed, especially with the cruise on. It’s using engine braking to help control speed.

If you started it cold and proceeded to immediately go downhill it very well could still have been in open loop, as well as cold trans fluid. They’ll behave differently in order to help warm things up faster and enter closed loop.

Once temps are up and your going downhill fast enough to allow the torque converter to lock up, you’ll be in decel fuel cut off and your engine won’t be using any fuel.

 

[bm02tj]

After 3-4 minutes warm up you go down the hill in 3rd gear no trouble no brakes
no high RPM
Yes it is the way they have programmed the truck to deal with emissions by making more

 

[Tach_tech]

After 3-4 minutes warm up you go down the hill in 3rd gear no trouble no brakes
no high RPM
Yes it is the way they have programmed the truck to deal with emissions by making more

It’s likely doing it then to reach temps faster where emissions are “optimal”. Unless you can view the injector pulse width with a scan tool you can’t really say how much fuel it’s using. It very well could be in fuel cut off, which uses zero fuel, all injectors are shut off.

 

[Brandon-w]

At startup all injected vehicles have higher idle and run rich to heat the catalytic converters up. Once it senses they are at sufficient heat it will kick down the fuel and run properly. I'm thinking you only notice it because of the hill. On the flat this wouldn't be an issue.

 

[bm02tj]

At startup all injected vehicles have higher idle and run rich to heat the catalytic converters up. Once it senses they are at sufficient heat it will kick down the fuel and run properly. I'm thinking you only notice it because of the hill. On the flat this wouldn't be an issue.

Correct It would take very little to program it to not do this as it is scary in winter unless you leave in drive and us the brakes
It is bad enough I could not get a manual transmission they have to do this
last truck still had original rear shoes and pads on the front replaced due to corrosion not wear in 250,000 Km

 

[Brandon-w]

Correct It would take very little to program it to not do this as it is scary in winter unless you leave in drive and us the brakes
It is bad enough I could not get a manual transmission they have to do this
last truck still had original rear shoes and pads on the front replaced due to corrosion not wear in 250,000 Km

This is true. If you asked you could get a tuner to delete that feature. Mine is deleted but I also deleted the cats. Also where in bc u from? I grew up around Prince George area.

 

[Wild one]

Correct It would take very little to program it to not do this as it is scary in winter unless you leave in drive and us the brakes
It is bad enough I could not get a manual transmission they have to do this
last truck still had original rear shoes and pads on the front replaced due to corrosion not wear in 250,000 Km

Other option is kick it into neutral ,if it's still in open loop /cold mode.

 

[Tach_tech]

Correct It would take very little to program it to not do this as it is scary in winter unless you leave in drive and us the brakes
It is bad enough I could not get a manual transmission they have to do this
last truck still had original rear shoes and pads on the front replaced due to corrosion not wear in 250,000 Km

Does it only do this with cruise on? Or doesn’t matter?

 

[ram1500rsm]

What happens if you don't set the cruise control and instead you hold the gear you want manually ?
I could see more people doing this going down hill than doing the cruise control thing which i figure you did for the test ?

 

[bm02tj]

This is true. If you asked you could get a tuner to delete that feature. Mine is deleted but I also deleted the cats. Also where in bc u from? I grew up around Prince George area.

2017 you can get into 2018 have the security module that you need bypass wiring and may void warranty
I have two brothers in PG I live in Kamloops

 

[bm02tj]

What happens if you don't set the cruise control and instead you hold the gear you want manually ?
I could see more people doing this going down hill than doing the cruise control thing which i figure you did for the test ?

I did this in 2nd and did the same I only used the cruise to prove it was all the truck not me

 

[tidefan1967]

I don't think its FCA necessarily. I use cruise control pretty much everywhere and at all speeds and I haven't found a GM or Ford truck (either)where the CC did a particularly good job at lower speeds and an even worse job when you threw hills into the mix. Did you try turning off the MDS first? It makes a hell of a difference with it off at low speeds(not sure what the min. speed it engages at though) since it causes the truck to lug so badly. I would definitely lock out the higher gears too.

 

[Tach_tech]

I did this in 2nd and did the same I only used the cruise to prove it was all the truck not me

What if you just leave it in drive? The trucks gonna do whatever it can to try to maintain a set cruise speed.

If you leave it in drive it will still downshift once it senses you’re braking down a hill but not to the high rpms you experienced.

 

[bm02tj]

I don't think its FCA necessarily. I use cruise control pretty much everywhere and at all speeds and I haven't found a GM or Ford truck (either)where the CC did a particularly good job at lower speeds and an even worse job when you threw hills into the mix. Did you try turning off the MDS first? It makes a hell of a difference with it off at low speeds(not sure what the min. speed it engages at though) since it causes the truck to lug so badly. I would definitely lock out the higher gears too.

The problem is the computer is adding fuel when I want the motor to hold me back with out using the brakes
I always cancel cruise on the highway so it does not gear down and do it manually if needed
This was only a test to see what it would do

 

[bm02tj]

What if you just leave it in drive? The trucks gonna do whatever it can to try to maintain a set cruise speed.

If you leave it in drive it will still downshift once it senses you’re braking down a hill but not to the high rpms you experienced.

left in drive it goes to fast so brakes are needed
The object is to use the motor to hold the speed down
When it stops adding fuel the truck slows and shifts up a gear like it should

 

[chrisbh17]

The problem is the computer is adding fuel when I want the motor to hold me back with out using the brakes
I always cancel cruise on the highway so it does not gear down and do it manually if needed
This was only a test to see what it would do

Is it possible the computer is adding fuel because the engine is still cold? If so, I thought that's what pretty much all modern engines will do. Waiting 3-4 minutes gets it out of open loop (like tach_tech mentioned) and so its no longer adding extra fuel to warm the engine up.

The faster they get up to temp the better for the environment (and maybe the engine).

My 8HP70 shifts different when its cold....something I fully expect because, its cold.

 

[Wild one]

left in drive it goes to fast so brakes are needed
The object is to use the motor to hold the speed down
When it stops adding fuel the truck slows and shifts up a gear like it should

At 67 years old,i think you're expecting it to act like a carb,and the newer fuel injection motors don't act like a carb when they are cold. My daily driver is a 1 ton GM,and it's horrible in comparision to my personal 1500.It'll gain so much speed going downhill,you need to ride the brakes,and hope to hell you don't ride them enough to warp the rotors,as it'll warp the rotors on a downhill coast in a heart beat.Take a GM for a drive even after it's warmed up,and you'll enjoy your Ram a lot more.

 

[Siff]

You are asking FCA to make the trucks emissions illegal so they run better. I think they tried that on another engine and it didn't go well for them...

You are better off buying a second ECM and all associated equipment and getting it tuned to (illegally) do what you want, then swapping back in the original equipment whenever you need warranty work done.

 

[bm02tj]

It would be a simple fix to use RPM instead for % of load which is what is causing the problem
And still keeping emission and warranty good