Hello all. Bus is a 06 International 300RE DT466E with an Allison 3000PTS trans.
Problem I'm having is intermittent loss of reverse "push button display shows an X when I press the reverse button. Ill clarify that this was intermittent about 3 times, and now no reverse at all.
I pulled 2 codes using the push button keypad:
d12312 - "Primary shift selector or RSI link fault"
d26600 - "Serial communications interface fault".
When i check the trans fluid level using the push button keypad, it says the trans is 7 quarts low. The trans is full on the dipstick, so apparently the trans sump fluid sensor is sticking or bad.
I have a Nexiq scanner with Allison version 8.4 installed on my laptop.
I cannot connect to the trans using the 9 pin Deutsch connector in the rear engine bay.
I can run engine diagnostics as well as Bendix brake diagnostics through this port, but not the Allison diagnostics.
I have read here that it may need to be plugged in to the Deutsch connector under the front dashboard. I have an open 6 pin male Deutsch connector there, as well as a 9 pin Deutsch male and female plugged together right next to it.
I was thinking that maybe my multiplexer module under the dash board went out, but wouldn't that cause other issues too?
Could the trans not go into reverse because it thinks it is 7 quarts low? But then, why would it go into forward?
Any help would be greatly appreciated!!!