Technical advice needed for reprogramming B500

[joel_newton]

My recent trip over the grades to Oregon and back has me moving the reprogramming of my B500 up on my To Do list.  The CMC options were programmed such that the transmission downshifts to 4th if the Jake is enabled and you apply the brakes.  This results in over-speeding the engine into the 2300s and occasionally bumping 2400.  You also end up around 45mph on downgrades when you could be going around 55mph with only occasional light brake applications.  Plus being annoying in other aspects. Can't understand why anyone would want this function enabled.   Gotta go!

I have the ProLink with the Allison Reprogramming card. I have the instructions on how to change options.  There are two CMC options related to this function.  It appears there might also be a related option in the DDEC III programming.  However, I am not about to jump in and make changes without fully understanding the options.  I don't have an Allison  programming manual that might help.  And,  I noted in the ProLink Manual they will not even sell a reprogramming card to anyone unless they provide proof of their Allison Certification. 

There is no longer an Allison shop within several hours of my home. No shops in the area qualified to make the changes.  This topic has been discussed before on the Forum.  I am hoping someone is familiar enough with these options to give me some direction.  Thanks!

[brmax]

It would be great to have some options for sure.
The last i remember 12 years ago you and by way of your shop were password enabled. This may need wifi initally as laptop and software was installed. And your correct they required your certifications from their training. Some of the prolink on allison was started early in the nineties and may work as stand alone. If so probably password assigned to the card.

Floyd

[belfert]

Interesting.  I have the same bus as Joel and my B500 also goes to 4th when the Jake is engaged.  My problem is usually the Jake doesn't slow the bus down enough.  I try to downshift manually to 3rd to make the Jake more effective, but you have to do it at exactly the right moment.  A lot of times I do it too late and the RPMs get too high.  The B500 will go back to 4th to avoid the RPMs getting too high.

Can't you just change the Jake brake setting to low or medium instead of reprogramming the B500?  I always use the high position and still often wish I had more braking.  (Yes, Jake brakes were adjusted by a Detroit shop.)

[luvrbus]

All the B500 transmissions I ever saw will drop 1 gear when you engage the Jakes could be yours had 6th locked out like Belferts and was unlocked and wasn't reprogrammed  
I'll ask Kevin or Don for you but I don't believe you can accomplish what you are seeking with the Pro/Link it takes the master reprogramming software from Allison,I have the same card for my Pro/Link as you not much you can do with it .
You need to be careful I know where there is another late model Prevost for sale now with rods through the block with a series 60 and B500 it bypassed 5th and went to 2nd gear at 70 mph what a mess    

[joel_newton]

Floyd:  ProLink will work as stand-alone unit.  Optionally it can be controlled through attached laptop.  Password is internal to WTEC system.  No WTEC/DDEC WiFi in this bus. 

Brian:  That is interesting.  On 6% grades, when this thing drops into 4th, it is almost like hitting the brakes.  It quickly slows you from 50s to around 45.  I found if I vary carefully backed off the throttle in 5th the Jake would kick in without downshifting.  It would almost hold me at that speed.  But, after a minute or two, I would pick up speed and needed a light brake application.  And, it would downshift.  Would have been perfect if it weren't for the automatic downshift.  Also really annoying on the flats in traffic. 

Blew out the muffler or exhaust pipe and it sounds like an off-road lumber truck with the Jake on.  Passing the "No unmuffled engine brakes $720" made me a little nervous (not going to stop using them though).  Tried the low/lower setting.  Same issues. Quieter - ?

Brian, does your bus your bus want to "go" at idle.  At 600 RPM mine will idle uphill.  When stopping, after Jake cuts out, you really need push on the brakes.  On other Forum discussions some posters have speculated that bus brakes are purposely designed that way so passengers are not slammed around. 

Clifford:  I don't believe 6th is unlocked. 6th is never displayed in the shift pad and I saw no reference to anything over 5th when browsing with the diagnostic card. But I've been wrong before.  I'll look further - wouldn't mind unlocking 6th anyway.

I do have the reprogramming card as well as the diagnostic card.  The steps for using it are in the manual.  The fact they would only sell reprogramming card to certified Allison techs is a clue that folks like me probably should not be making changes without. 

Thanks for sharing the story about the Prevost.  Now I REALLY want to eliminate this option.  The ProDriver popping messages that I was exceeding the 2200RPM limit was concerning but the tach was only going up to about 1800 - 2000.  I installed the Silverleaf VMSpc system and found the tach is WAY off.  2300s and sometimes 2400s.  I know with Jakes on the normal engine red line can be exceeded to some degree.  But, the down-shift is quite abrupt and likely stresses the drive line and engine in addition to the over-speed. 

[TomC]

This is an easy fix. Just turn off the automatic downshift when Jake or Brake is applied. I much prefer having it off and then manually downshifting if needed. Then keeping the Jake on all the time isn't such a problem. The transmission will still automatically downshift when Jake is applied-just at a much lower rpm.
2300-2400rpm is THEE absolute highest I'd spin a S60. Cruising wise, the S60 is happiest at 1400-1600rpm. Good Luck, TomC

[joel_newton]

Thanks Tom - we are in total agreement.  You certainly validate the issue of over-speeding.  My concern is making changes without benefit of someone who is familiar with B550/WTEC programming.  In browsing I can see the two CMCs related to this function.  But, I did not go into programming mode to see what values are applicable to the options.  The correct values may be obvious.  Still hesitant to jump in and make changes.  In your post of 2007 you mentioned value options.  May I contact you via email for clarification?

[belfert]

My WTEC was sent to someone and reflashed using the program for a different bus to enable 6th gear.  The reflash did not change how the Jake operates.  It still drops to 4th gear when the Jake activates.  The transmission still works every bit the same as before the reflash except 6th gear is usable.

There is a programming problem with the transmission and the Jake when cruise is enabled.  If the road speed increases more than about 1/2 mile an hour while on cruise the computer will engage the Jake.  Sometimes on a gentle downgrade this might happen five times in a minute.  It can't be good for the transmission to shift that many times in one minute.  I keep the Jake turned off when not needed.

[joel_newton]

I literally just put down the DDEC Troubleshooting Manual.  Rechecking to see what, if any, options related to the downshift in question.  The one I found is informational only - no control.  However, a number of the cruise control options relate to your issue.  I'd be happy to copy the pages (as pdf) and email them to you.

[luvrbus]

You can open the down shift operation with your software and make a few changes to the rpm ,I have the 600 page Principles of Operation manual for the B500 but I cannot find a way to turn the automatic down shift off.
Belfert needs to have his reprogramming checked some how his is not reading that the transmission is a 6 speed,I'll say it again all the B500 will drop 1 gear when the Jakes are activated.
You could call Bobby at Global Transmission in Tuscon if there is a way him or Kim can tell you how to do it,I am still trying to figure all this electronic BS out myself         

[joel_newton]

Clifford my manual lists what I GUESS are the two relevant CMCs.  "Eng Brake Preselect Shift Position" and "Eng Brake Preselect Shift Schedule Select."  In Tom's post of several years ago he gave descriptions of what are probably values for one or both of these options.  I am reluctant to even go in reprogramming mode without some experienced direction and backup.  Ill keep Global Transmission as a "silver bullet" option.  Betting most outfits would be quite reluctant to help someone they don't know over the phone.  I'd be willing to ship a couple cases of beer if they did. LOL

At the time of my manual 1998 there were apparently six "I/O Packages" for the WTEC transmissions.  Perhaps not all included the ability to enable 6th gear.  I do see a couple of references to 6th gear but they are not for enabling it.  Personally the only options I would ever touch are those intended for customers to modify.

Thanks for your suggestions.

[luvrbus]

Bobby and Kim will help you the guys at United would to but lost their Allison dealership,and you are right that is one high dollar transmission to be fooling with not knowing what you are doing lol when I don't know I call.
I am trying to find Kevin's (azdieselman) number for you but it may wait till I get home he is pretty sharp on the electronic transmissions   

[buswarrior]

Hold the phone. I drive in a mixed fleet, that won't change the factory settings.

The MCI would do this "dive to 4th" with the jakes, which pissed this professional driver off...

The Prevost would just stay in 6th gear on the Jakes, leaving the decisions to this professional driver to drop more gears, if I need to.

There has got to be a way to get the transmission to ignore the Jakes...

Beat that %E^&$%&%$ into submission!!

happy coaching!
buswarrior

[joel_newton]

Update: Success

Recently I finally had time to do a more indepth analysis of the engine overspeed on downshift when the jake is enabled.  Not only was the ProDriver warning of engine over-speed when downshifting from fifth to fourth, it was also reporting over-speed when downshifting to lower gears. In my opinion, this behavure is not acceptable.

ProDriver reported that engine speeds were exceeding 2200 RPMs.  The after-market tach, while accurate idling at 600 and 1000 RPMs, grossly under reports engine RPMs over 1000 and never indicated RPMs over 1500.  I had installed a SilverLeak VMSpc system on a tablet.  I began watching the RPMs as the transmission downshifted. It was showing RPMs over 2400RPMs.

As previously noted, this engine over-speeding is related to the Allison transmission option "PreSelect"  From what I read, this option is often ("normally" ?) set to fourth gear.  Allison documentation states the transmission is designed not to downshift such that it over-speeds the engine over 2500RPMs. 

Finally ran diagnostics on the transmission. Found that PreSelect was set to SECOND gear.  That explains why why the engine would periodically over-speed as the transmission downshifted to each lower gear.

Since I could not find anyone locally who could modify this option I crossed my fingers and did it myself.  I changed PRESELECT to fifth gear.  WOW What a difference.  With the Jake on the transmission downshifts as it normally would without the Jake.  Downshifts are smooth - not jerky and do not over-speed the engine.  I do have to use the brakes a little more but - preferred to damaging the engine and driveline.  If I want more engine braking, I manually downshift the transmission.  Downshifting from fifth to fourth at 50MPH only brings the engine up to 1800RPMs (if I remember correctly - might be less).  Haven't had a chance to test it on the long 6 and 8 percent grades yet. No doubt it will work perfectly.

As a couple of others have noted; why sacrifice passenger comfort, and engine/drive train longevity for the sake of minimizing brake wear and tear.  Need the extra braking effect that comes with higher engine speeds - push the downshift button.  Hey BusWarrior - I beat the #$^*%&*^&)*( into submission!   LOL

[Bill Gerrie]

Cliff is right. I don't think you can change much. Attached is the reprogramming manual for the Prolink cartridge.
If it doesn't attach properly email me next week at retiredbusnut at yahoo.com