BCM Community
Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: mqbus767 on August 21, 2024, 03:25:40 PM
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Hello Bus Nuts,
I'm currently 10 miles outside Springfield MO off I-44 at Hood's Truck Center with a broken down bus. We were driving on the highway when all of a sudden the bus would not accelerate beyond about 40MPH. I also noticed at the same time the spedometer wagging back and forth. I was able to limp off the interstate and pull into the truck center. I noticed that the Allison keybad (WTEC III) was not illuminated. I shutdown the bus and began some troubleshooting, but found nothing out of the ordinariy. I've checked all ECM fuses and the WTEC fuse; all good. I checked and swapped some relays in the front J box, but nothing changed. I don't think the relays have anything to do with it from the labels. The bus will not start.
The transmission was quite a bit low on fluid so I'll be adding more, but from all my research a low fluid level should not cause the keypad to go dead. I pulled the keypad apart and verified that the circuit board is getting 24V.
At this point I'm sending the family back to Houston in a rental car while I remain with the bus to get it fixed/recovered. I've located a couple of keypads at various and extortionary prices, but I'd really like to know for sure it's the keypad before I invest in that ebay purchase.
Any ideas or help would, as always, be much appreciated!
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On my bus when the speedometer was wagging back and forth the power line to the meter was not hooked up. (partial dash conversion by a previous owner.)
I believe that is an electronic transmission so a loss of power would inhibit it's ability to shift.
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Some of my gauges on my dash wagged back and forth when my starting batteries were low, but I don't recall which gauges. Once I replaced the battery with the dead cell, everything went back to normal. Maybe a battery and/or alternator (low power) problem is causing all this??? Only a guess!
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I checked the battery voltages and they are 12.8 and 12.9, so I think they are OK. Everything else on the bus seems to work OK. The gauges sweep when I power up the bus, but the keypad gear seven-segment display is black and the start button does nothing.
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I found a place in Springfield that will bench test the keypad and TCM. Crossing my fingers that it's the keypad.
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Uber'd to Central Power Systems and Services in Springfield with my keypad and transmission ECU. They bench tested the ECU but could not get it to connect. The tech there was pretty confident the ECU is dead. I was able to locate a used one for sale from Fowler's Autowrecking with a 6 month warranty. It's being shipped to me and should be a plug-in replacement. It's not a 100% guarantee that the ECU is programmed the same as mine, but the CIN and other numbers do match. I called Fowler's to explain the situation and it sounds like I should be able to just plug it in and go. Stay posted!
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They all have the same perimeters even if the programing is not the same you can toggle the right perimeter with a Pro/Link ,you should have gotten a cat eye on the pad with a bad ECM you may have a dead pad too lets hope not .One has to love the 3 to 5k electrical glitches :(
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As a part of the bench test they connected a known-good keypad; no cat eyes, no nothing. We shall see...
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As a part of the bench test they connected a known-good keypad; no cat eyes, no nothing. We shall see...
Save your TCM they have a fuse and backup battery inside the module you may get lucky and have a spare for a few bucks
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With nothing but time on my hands, I went ahead and opened the ECU. The burnt electronics smell was strong and I located a blown transistor. It got pretty hot because it scorched the IC on the opposing board. I don't have a circuit board schematic, so I'm not sure what the transistor was driving. I guess my fear now is that whatever device is connected to that/those pin(s) is shorted and could(?) be blowing the transistor. My gut tells me that surely Allison has some sort of dead short protection on this ECU, but who knows.
Does anyone have any experience with the internals of the WTEC III ECU? Does anyone know of a shop that remans them and might be willing to look at a few pictures for me?
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I have the rare principals of application manual, if i get time Sunday will check and see if it in it, probably does it has a ton of fold out pages covering the WTlll electrical and hydraulics
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Looks pretty smoked. Over voltage possibly?
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I think an overvoltage on the TCU is less likely, but possible.
In my searching, I found an RV owner that had a similiar thing happen on his rig. A cap smoked on his board. He seems to have had more moving parts than I did with the storage facility moving his rig. Interestingly his TCU seems burned up in almost the same spot as mine:
https://www.youtube.com/watch?v=Lx80avW6s24 (https://www.youtube.com/watch?v=Lx80avW6s24)
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Just heard back from a tech at Transmission Instruments (https://www.transmissioninstruments.com/ (https://www.transmissioninstruments.com/)).
"Hi,
Yes this is a common failure in the WT3ECU909 & WT3ECU910 models. In all the cases I've seen this is a internal failure not caused by something on the vehicle.
"
So that gives me a boost of confidence that I'll be able to swap it out without immediately blowing the reman. Now the only remaining question is about programming. I told Fowler's exactly which drive train/bus I have and they should have shipped me a TCU from the same setup. Hopefully getting closer to getting her patched up.
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Good news indeed. Here's to getting back on the road soon!
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Well, good news and bad news. I got the replacement TCU installed and the bus started up no problems. However, when I go to shift into gear, the 6 or R just flash and prevent me from actually going into gear. I suspect now that it's a programming issue. Without the old ECU, the shop can't pull the programming, so I'll have to have them reach out to Allison or maybe MCI to get the programming and flash the TCU. Looks like I'm here for another day at least. Thankful for the progress though!
BTW, all the numbers on the old and new TCU matched.
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It is looking for a lockout like a handicap door,if they are real low on fluid it happens,do you know how to pull the flash codes from the pad ?
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I checked the diagnostics register; no codes set. I agree, I think it's looking for some sort of interlock that existed on the previous vehicle but not on mine. Hopefully a reflash will get me back up and running.
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FIXED! It took a tech from Central Power Systems and Services a couple of hours to figure out which magic setting needed to be disabled in order to make things work again. Once he found that, all was good. We took it for a test drive, all gears forward and back are working. It's unfortunate that I didn't have the programming file from the old TCU (and the old TCU is completely dead) because I could have probably saved the $700 road side repair. Also, the replacement keypad was unnecessary, but I didn't want to wait another week to find out it was also bad.
I'd recommend to any other WTEC III owners that they purchase a backup TCU and have it reconditioned/programmed to their current settings. At the very least, get your bus into a shop and have them pull the settings and email you the file. It would have saved me time. money, and anguish.
Because I'm always planning for breakdowns, I thought this price breakdown might be useful to other bus nuts:
$450 - Keypad (Not needed)
$200 - Used TCU (Same CIN, model #, etc.)
$400 - One weeks' worth of hotel
$700 - Tech road side visit to reprogram TCU
$250 - 5xUber trips
$230 - Rental car to Houston for family
Total -> $2480
Special thanks to Gary and Tina at Hoods Motel and Allison at Hood's Family Restaurant. They made me feel comfortable and were very accomodating of the bus for the entire week.
Thanks also to Warren and Pinky at CPS&S for the phone support and being willing to work on an "RV". Not many are these days.
And, thanks to Glennman for checking in on me and offering his advice. I appreciate your encouragment brother!
Back on the road in the morning and hopfeully home before evening!
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FIXED! It took a tech from Central Power Systems and Services a couple of hours to figure out which magic setting needed to be disabled in order to make things work again. Once he found that, all was good.
Total -> $2480
Back on the road in the morning and hopfeully home before evening!
Since you haven't chimed in again, its great that you made it home for the rest of your holiday weekend.
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Thanks freds! I did make it safely home and back to my family. The bus did great the whole way including in the slowest crawl I've ever done through Dallas; stop-n-go from North to South. Our next trip is planned for October, but it will be a local trip. Long-term, I'm going to get a remanufactured TCU to have on board. Hope my experience is helpful to all 102/Allison owners. I know I leared tons!
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Owning a electronic engine and WT Allison ,a Prolink is a better investment than spare TCU INMO one cannot do programing with the Pro/Link but you can toggle the perimeters. A Silverleaf will monitor the engine and transmission for a minor problem before it becomes a major problem, dealers charge from $150 to $250 just to plug a scanner in now.Allison has been successful in keeping a tester off the market to shift the WT with a bad TCU, how much longer is a ? I have tester I can shift the electronic 480 E transmission in GM products even with a bad TCU,the mobile guys have one for the Eaton to gets trucks off the road to a shop
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The biggest issue for the future is the continual march of manufacturers towards preventing owners/mechanics from repairing their own equipment. Manufacturers have taken extensive measures to make it difficult or impossible to repair equipment without going back to them and paying exorbitant prices for the "right" to repair. Consider the cost of tools needed to maintain my 23 year old bus:
$800 - Nexiq
$995 - DDL software license/per year
$600 - Allison DOC software license/per year
$400 - Bendix Acom software license/per year
You might be able to rationalize this kind of cost if it was a one-time investment in a set of tools that could support the bus for the rest of it's life, but charging owners $2000 in software licenses per year for no additional benefit is extortion in my opinion.
Combine this with the latest practices from manufacturers like John Deere that are now employing encryption and other technologies to make it even more difficult to fix/modify vehicles and you quickly realize that their top priority is locking in a customer to a lifetime of dependency on their licenses and repair networks. This is something that technology companies have been guilty of for decades. When digital technologies started making their way into every aspect of a vehicles system, these nefarious practices follwed with them. The bright spot in recent years is the rise of the "right-to-repair" movement. Legislation is now in play in many states and federally to require manufacturers to provide tools and information to allow owners to repair their vehicles, electronics, and agricultural equipment.
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There a lot of software out there still for sale for 20 year old buses ,you don't have to pay to link to a main frame,I bought my DDL and Allison DOC out right years ago for under $1000.00 and the Bendix software was tossed in for free.I have 2 older lap tops loaded with Cat,Cummins,Detroit engines and WT and ATEC transmissions all run off of windows.all the older software was window based off a laptop You are not going buy software for any diesel engine and running gear made after 2010 unless you pay the fees or take it to a shop
One cannot put all the blame on the manufactures our EPA took the software out of the hands of the public for their emissions std and not only for highway vehicles, you don't call and say I want to pay for a license for the software .My son has a new John Deere tractor you cannot do S*** without paying JD $1500.00 a year and the application was 4 friggn pages to fill out and took a law suit against John Deere for people to access to the software