I member asked that I repost this.
If you need your Allison ECU or shift pad repaired, this is THE GUY:
Transmission Instruments (https://www.transmissioninstruments.com/)
His site also has an excellent Troubleshooting section that can help you diagnose the issue.
And when John decides to retire, I sure hope he has someone in line to keep his business going. It would be a shame to lose this valuable resource.
John IS retired. His son, Vojta runs the business: About – Transmission Instruments (https://www.transmissioninstruments.com/about-2/)
If you ever see the dreaded "Snake Eyes" (photo below) on your transmission gear selector panel, then you need to visit the website recommended by Brett (above).
Vojta was great to work with and excellent communication. My buttons were no longer responsive and he rebuilt them and now I no longer worry if it will shift.