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Camcues · 07-27-2021, 06:11 PM

Great info StevieB we just bought a 2003 Winnebago with Allison 1000 and after reading your write up I believe I'm having same issue. What code reader did you get to read trans codes
Thanks

allison_tech · 09-03-2021, 06:17 AM

Quote:

Originally Posted by stevieb5346

Ok I have checked and cleaned the ground wire that goes from the battery to the engine block on the passenger side then there is a flat grounding cable that goes from the engine to the frame on the rear drivers side of the engine. I have checked and cleaned the connection. their too I have checked the ground and power input at the TCM harness. My tech2 software is showing code P0880 TCM Power input signal and only throws this code after it warms up. Also throwing code P0872 Transmission Pressure Switch Solenoid E stuck or close again only when it has warmed up but here is the crazy thing turn the ignition off count to 5 start it back up go backwards and forwards a few times or until it acts like it pops out of gear throws the codes and turn it off and it does the same thing drives great and runs great until it does it again. I have added a link below to my google drive showing the snapshots from my Tec2 software the .pdf file is a log of all the data from the trans up to when it pops out of gear. If anyone has any ideals it would be greatly appreciated if you could share them with me.

https://drive.google.com/drive/folde...6k?usp=sharing

Whenever I had an Allison trans setting 0880 codes I always ran new power wires with 10amp fuses and new grounds, directly from the battery. Chances are depending where the TCM is and the batteries are located, unless close in proximity you will never find where the damage is in the circuit.

CamJam1 · 09-03-2021, 09:02 PM

I'm curious to hear what progress the OP has made.

stevieb5346 · 09-04-2021, 09:11 AM

Quote:

Originally Posted by CamJam1

I'm curious to hear what progress the OP has made.

I drained the fluid and dropped the pan all looked good in the pan. Since the TCM was throwing P0872 which indicates Pressure Switch Solenoid E stuck or closed and from every thing I have read this is usually caused by dirt and debris in the valve body so I went ahead and ordered a remanufactured valve body for $399.00 which included a new pressure switch and all the solenoid's and valves in the reman unit are hydro tested to make sure they are all functioning properly I removed the old valve body and installed the new valve body replaced the internal filter cleaned the pan out and put it back on. Even though I had just flushed the system with new external filter and new fluid. I went a head and filled it up with new fluid and replaced both filters started the engine cleared the codes and took off on a 50 mile test drive no light no limp mode shifts great I have since put over 5K miles on this baby when out west the the Arizona desert with temps of 110+ and through the New Mexico mountains the RV performed flawlessly. Just goes to show you their are very few honest shops and ppl that are in business today.

stevieb5346 · 09-04-2021, 09:24 AM

Quote:

Originally Posted by Camcues

Great info StevieB we just bought a 2003 Winnebago with Allison 1000 and after reading your write up I believe I'm having same issue. What code reader did you get to read trans codes
Thanks

The scanner I use is the VXDIAG VCX Nano GDS2 and Tech2Win Diagnostic Programming System for GM/Opel WiFi you will need a laptop running window it actually come with a copy of the GM Tech II software how they are getting by with this I don't know. The software is a bit tricky to install but if you have a bit of tech knowledge and follow the instructions it works great. I purchased the usb wired unit and sent it back the WiFi system is only $10 more.

https://www.amazon.com/dp/B06XDHF3XX...NsaWNrPXRydWU=

allison_tech · 09-05-2021, 09:42 AM

Just in my experiences with stuck valves. If you remove the valve body and completely disassemble it and clean it. Fund the stuck valves, clean bores properly. Replace solenoids, harness and pressure switch plate. You should be good. 399 seems very cheap for a new valve body

stevieb5346 · 09-06-2021, 08:31 AM

Quote:

Originally Posted by allison_tech

Just in my experiences with stuck valves. If you remove the valve body and completely disassemble it and clean it. Fund the stuck valves, clean bores properly. Replace solenoids, harness and pressure switch plate. You should be good. 399 seems very cheap for a new valve body

In my write up I stated this was a re-manufactured vale body from valbods.com they also have a eBay store they sell a used valve body's which are just cleaned and hydro tested as you explained. At the time I spoke with them the price was $179.00 90 day warranty. They also sale a re-manufactured vale body which includes all new solenoids, springs, plungers, pressure switch and internal wire harness which is also hydro tested and comes with a 12 month warranty $399.00. After taking this coach to two different authorized Allison transmission shops handing them the the codes from my diagnostic testing the first one said it was the main pressure switch and internal wiring harness. The second one sated I needed a new transmission at the cost of 7K to 10K so in my opinion using authorized means nothing anymore. If your not able to do it yourself find you a good honest transmission shop.

allison_tech · 09-08-2021, 09:54 AM

Could always pull the pan off and drop the valve body and find the stuck solenoid valve. If it's actually stuck. You'll know it won't come out of the valve bore.

Chatham · 10-01-2021, 07:00 AM

Hi
I have newer Allison that yours but similar symptoms years ago with chassis battery dead cell that caused trans module to intermittenly lose 12v and that hiccup disables trans pad; not fun on the Interstate !

Patrick