Newell Gurus

Full Version: Transmission not engaging
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Have a 1994 model year with the DD8V92 and allison trans.  It would not go into gear foward or reverse until I reved the engine up.  Impending failure or loose wiring?
Frank,

Check your high idle switch. The transmission will not shift if you are in high idle.

You can use the control pad to check the oil level in the trans…have you done that? I forgot the key sequence…but there are threads on here that talk about it.

Bill
Hmmmmmm, did you happen to notice your air pressure? Does you tranny have an air shifter? Or does it have an electronic keypad?
Frank's coach is #349 with the HT741 controlled with a keypad with RND321 buttons.
Thanks Michael, as usual I am way off base.

The only thing I can offer is a random observation on my own coach. Sometimes if I just turn the switch and crank, the tranny will not go into gear. I get the ‘cat eyes’ on the display. If I am patient enough to allow the DDEC computer and Allison computer to go through their startup dance which is completed when the check engine and stop engine lights go out, then I never have this problem.
Check the throttle position sensor 
I had same issue with a different coach
What does the momentary DDEC toggle switch on the dashboard do?
If the DDEC shuts down the engine, holding the toggle switch in the on position will allow the engine to start to get you off the road.