:-/I have a 93 nissan sentra auto xsmn. Suddenly it won't shift out of the low (first) gear. Otherwise, the xsmn works fine. No strange noises and the fluid is OK. I'm wondering if a sensor would cause this? One mechanic said a xsmn replacement would be necessary! Sounds like overkill to me! Could I possibly troubleshoot be the computer diagnosis? Thanks for the input! :-/

Has the fluid and filter been changed? With the car being over 10 year old, I am sure it is past the recommended interval. Servicing it now, might or might not correct the problem. Neglect can lead to expensive problems. Even with proper maintenance, things still go bad sometimes. Before I paid for a new transmission, I would check elsewhere.

Thanks for the speedy reply! The nissan sentra has 80k for mileage and the xsmn fluid and filter were changed at 50k. Fluid doesn't smell burnt. Do you know of any sensors or i.e.. A modulator valve that would prevent up-shifting?