dbarton291 - 12/24/2008 5:20 PM
lenhenderson - 12/21/2008 5:55 PM
Just drove Prevost Coach with T741 Allison Transmission 200 miles without a problem. Then stopped for a moment with engine running and put in nuetral. Now transmission won't engage --- neither drive nor reverse. Help please with suggestions.
I assume you mean HT-741 transmission. Is the check trans light on? Any trouble codes?
1. Make sure the engine high idle is not active.
2. Sometimes they don't engage if the throttle sensor is misadjusted and the trans ECU thinks you're above a throttle position at which range is inhibited. If this is the case there won't be any lights or codes.
3. If the engine is a DDEC engine, the trans ECU may be getting its throttle information directly from the engine ECM in which case, the throttle sensor will be be present.
Need to define exactly what hardware you've got to limit the possibilities. If no lights or codes, I usually try to figure what the ECU could be thinking that would not allow drive to be engaged. Usually, there's an inhibit somewhere that's active or malfunctioning.