3000 Temperature Issues

[SAS30]

2014 Newmar D Star 38 ft with Allison 3000,
While servicing the coach this week, I noticed that the trans temperature that is shown on the dash wasn’t coming up.
Had engine on high idle and engine temp 170-180.
And the trans temps were bouncing back and forth from 0 to less than 50 degrees. I noticed this 2 days in a row.
The outdoor temperature has been lower(mornings in the 30’s) than the previous few weeks , so I didn’t think much about it.
Thinking after it has been on the road a few miles the temp would come up.
Wrong!
After being on the road for 150 miles, all was well and trans shifting properly, but no change in the trans dash temp readings of 0-50 degrees.
Then, running 60 mph in traffic on I 285 around Atlanta, the coach just quit pulling.
Of course , I panicked and let of the accelerator. Carefully making my way over towards the next exit, which luckily was just a short distance ahead. Due to heavy traffic had to stop on the exit ramp and after putting in neutral then reverse then drive it pulled forward.
No dash lamps, codes or any other info.
It does have info on the shift pad read out, ‘low temperature’ and ‘ low fluid level’.
However when the fluid is checked manually or by with the shift pad, both show fluid level is fine.
After pulling and pushing on the wire harness from the transmission, the dash temperature readings have become higher(70-120 range) and haven’t had any other shift issues for the additional 90 miles of our trip.
Thinking that the erratic temp readings possibly confused the ecu that controls the trans and possibly shut the trans down to protect it from possible temperature related issues.?
Any Allison gurus on here that can weigh in and help me out?
Thanks

[rag_ftw]

I'm certainly not a guru but if that happened to me the first thing I would do is unplug and replug every connector associated with that harness, hoping I had some corrosion in a connector. (I always do the easy/cheap stuff first!)

[SAS30]

Found a shop that seems to know Allison transmissions. FDDA-Florida Detroit Diesel Allison. They have several locations across the state of Florida. I chose the Ocala location and have an appointment 4/10. Service manager and tech helped diagnose the issue by phone and gave an estimate of the repairs and are holding the parts needed until I arrive.. I’ll report back after the repairs are complete.
GrAndy

[Lowflyer1]

The coach has to be driven probably 1/2 hr to get the trans to the proper temp.

I've never looked at the temp while idling but use the key pad to check the level at the end of an extended drive. The level does not show until the trans fluid temp is in the proper range.

[SAS30]

Wanted to post the results of my Allison 3000 service at Florida Detroit Diesel Allison in Ocala, Fl.
Problem was mostly what they diagnosed per the phone conversation I had with them 3 weeks prior. Seems that the internal wire harness which also comes with the temp sensor and level sensor , was defective. After replacing the tranny shifts smoother and all sensors are working as should.
I could have replaced the part myself and remedied the issue of erratic temp and level issues. While saving around $1200.
But I am no expert on these and with their vast product knowledge and ability, they knew to replace the internal filter spring with an updated one, and also updated the software to new and better operating data( if that is correct terminology).
Being a 4th generation 3000, mine had the updated TCM(trans control module) which saved me about $1500.
Highly recommend this company for any Allison Transmission issues.
We overnighted in their parking lot, which is spacious. They only have one 50 amp connection( 1st come gets it). But we opted for a more level area as the weather was cool that evening.
The Cummins shop is right across the street. Obviously it’s a good shop also, as their were a dozen motorhomes there for service.
FDDA also has several other locations in Florida. Check out their website for those
Also several nice RV ‘Resorts’ close by if you need to come early or stay later.
FYI, GrAndy

[Lowflyer1]

Thanks for the update.
But is this response to your original "problem" and now you get the trans up to proper temp with just high idle?

[SAS30]

Originally Posted by Lowflyer1

Thanks for the update.
But is this response to your original "problem" and now you get the trans up to proper temp with just high idle?

I apologize for the long delay on responding to your comment. I didn’t see it until now. My original problem was that the transmission disengaged in traffic. Found out it was due to the temperature sensor in the transmission sending erratic signals to the TCU. After replacing the sensor all works well.
I don’t really concern myself about warming the transmission as much as I do the engine, but it does now show that the transmission temps are coming up as the engine warms up. I have a trans temp indicator on my dash which I paired on the same screen with the engine temperature and I monitor both when warming up for travel.

[Lowflyer1]

Thanks for the update.