Relearns shift pattern every day
Thread Starter
|
2nd Gear
Joined: Dec 2022
Posts: 2
Likes: 0
Relearns shift pattern every day
I have a 2006 E450 Ambulance with 6.0 diesel. 33k miles.
Everytime I start it up, it has low power and takes forever to shift. Not really though. It will shift a little over 3k but takes so long to get there. I end up letting off the gas at 2500 rpm to let it shift. After it has gone through the first 3 gears, come to a stop and go again, power is normal and it shifts normal.
Fluid is clean and full.
I was told this was typical and that the truck is relearning shift patterns. That this can be turned off with the right diagnostic tool.
Does anyone know whats going on? Is it safe to turn off the relearning bit.
Everytime I start it up, it has low power and takes forever to shift. Not really though. It will shift a little over 3k but takes so long to get there. I end up letting off the gas at 2500 rpm to let it shift. After it has gone through the first 3 gears, come to a stop and go again, power is normal and it shifts normal.
Fluid is clean and full.
I was told this was typical and that the truck is relearning shift patterns. That this can be turned off with the right diagnostic tool.
Does anyone know whats going on? Is it safe to turn off the relearning bit.
Cargo Master
Joined: Oct 2003
Posts: 2,833
Likes: 5
From: Jefferson, Iowa
I doubt it is relearning at every start, I would be more inclined to suspect injector stiction or a boost issue (dirty ebp sensor, restricted map sensor hose nipple or sticking veins). I would try a simple oil additive called archoil 9100 and if it gets better. stiction is mainly seen when the engine is cold.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,734
Likes: 2,663
From: SE Florida
The transmission does not learn shift patterns. That is not what is happening.
Does your truck have a power disconnect? Are you shutting off power to the PCM with some method other than the key? If so, it may be relearning the axle ratio. It will do that if the PCM loses keep alive power. This is supposed to only happen when the battery is disconnected, or someone manually clears the keep alive memory.
Does your truck have a power disconnect? Are you shutting off power to the PCM with some method other than the key? If so, it may be relearning the axle ratio. It will do that if the PCM loses keep alive power. This is supposed to only happen when the battery is disconnected, or someone manually clears the keep alive memory.
Logistics Pro
Joined: Jul 2014
Posts: 4,673
Likes: 532
From: Houston, Texas
Definitely acts that way cold. Do you let it warm up at all? And, the PCM can also increase fan speed when it's cold, kinda like taking a deep breath. I assume you know the difference, but with my first diesel, the first time that fan came on, I thought it was the transmission slipping - as I gave it more pedal, it sounded like the engine rpm kicked up considerably, yet the truck didn't go any faster. It was just the fan noise. That was an Fseries, and it seems like to me that these Eseries hit that fan more often, and more at start up, prolly because of the small engine compartment.
Thread Starter
|
2nd Gear
Joined: Dec 2022
Posts: 2
Likes: 0
The transmission isnt slipping. Its just very slow through the first set of gears. I lose patience somewhere around 2500 rpms and left off the gas to let it shift. After it has gone through the gears once, it goes like a dream. I do have a manual disconnect for the batteries. I am leaving it connected for now to see if that makes a difference. I only drive it once a week and don't know how long or how many miles I need to drive it before I can say whether me disconnecting the battery is the problem or not. I am also looking into finding someway to keep the memory when I disconnect the battery. Plugging something into the OBD 2 connector over and over doesn't seem like a great idea to me. Seems like I will end up wearing out that connector eventually or breaking it.
I wonder though, If I continue to disconnect the battery when I park it and make it go through this process every time I want to drive it, will it mess something up eventually? Like the transmission.
As far as it being cold.... I drove it to work one morning, left the batteries connected and on my way home that evening it did it again. I suppose I can find a day to crank it up and drive it, park it, wait an hour or two and see if it still does it. How cold does it need to be for it to be a injector stiction?
I wonder though, If I continue to disconnect the battery when I park it and make it go through this process every time I want to drive it, will it mess something up eventually? Like the transmission.
As far as it being cold.... I drove it to work one morning, left the batteries connected and on my way home that evening it did it again. I suppose I can find a day to crank it up and drive it, park it, wait an hour or two and see if it still does it. How cold does it need to be for it to be a injector stiction?
Hotshot
Joined: Apr 2010
Posts: 19,072
Likes: 242
From: Saratoga Springs,UT
Well if you disconnect the battery constantly that would explain it it’s forcing relearn
it may take multiple drive cycles to meet drive cycle requirements mpg shifting points working EGR systems things of that nature relearn in this process
it may take multiple drive cycles to meet drive cycle requirements mpg shifting points working EGR systems things of that nature relearn in this process
Thread
Thread Starter
Forum
Replies
Last Post
