Allison 4000 reprogramming ideas

[Jerry Emert]

Since I am taking the Coach to have the transmission cooling checked out tomorrow I started wondering about the programming ideas I've seen here.  Like Jake brake activate without downshift so you can do it manually.  Or hydraulic fan does not activate with the Jake.Not sure that I want to do any of them but this is an easy chance to without making a special trip.  Any ideas you would care to share would be appreciated?
Thanks in advance.
Jerry

[Mike Groves]

Regarding the Jake Brake with no downshift, just keep in mind that part of the power of the brake is in the engine and that's why the downshift is programmed because it generates higher rpms and the higher the rpms the more the braking force.  If you have to think to do two things (select jake, plus downshift) at once in a situation you really need heavy braking then I doubt you'll get it done.  The way its programmed now you get the engine braking immediately.

If this doesn't make sense just look up how the jake brake works in your cat engine manual.

Mike

[David T. Richelderfer]

If you have the transmission reprogrammed to not downshift when the Jake switch is ON, then the Jake can be left on at all times and the moment you take your foot off the accelerator OR touch the brake to disconnect cruise control, then the Jake comes on immediately.  Without the reprogramming the Jake cannot be left ON because whenever you release the accelerator or cruise control to slow down by coasting into a rest area, for example, then the transmission will downshift from 6th to 4th in about 1/2 second.  I MUCH PREFER the reprogrammed transmission to not downshift automatically from 6th to 4th.  It allows me to have the Jake switched ON almost all the time while travelling.

[Dale Wiest]

Mine is programed also to not downshift when the jake is on. I leave my Jake set on the max all the time.

[Jim Nichols]

We had Allison reprogram the mode button to always be in economy mode.  If power in hills was needed then we would push it. We were always forgetting to set it in economy mode. Just a thought.

[William Jordan]

Lots of ways to go I guess. Ours came to us   programmed to attempt 4th ( It wont go down unless engine is in right range. But also if the Jake is on it disconnects the Cruise and the cruise cant be engaged until the Jake is in the off position. I need to look at the options. I was told not to exceed 2000 rpm on the c12 but with the jake on it will downshift to about 2300 rpm in all gears on the way down.

[David T. Richelderfer]

Mine did too... about 3 times... and it felt and sounded like the engine was going to fly out of the coach.  I had the Allison reprogrammed within a few months after I purchased the coach.  I try very hard at all times to keep the engine from exceeding 2000 rpms.