Transmission Question

[RustyButTrusty]

Hi everyone. I have a 88 pathfinder se. I have noticed recently that when the transmission has finished shifting (45+ mph) it tends to almost jump in and out of a gear (or maybe torque converter). It always happens around the same spend and it tends to occur when I'm driving on a flat part of a road (not much load) and not accelerating. When I pushed the power switch (power light on) the engine runs at higher rpms and doesn't ever do it. It only does it when not in power mode. I have also noticed that when I am coasting down a hill around the same speed no acceleration it does something similar. You can watch the tach and see the rpms surge from around say 1800-2000 or so not alot, but the noise in change of engine speed is audible. I just was wondering if there is some sort of sensor or something that has gone bad that I might could replace to fix this problem. Thanks!

Edited October 25, 2011 by RustyButTrusty

[RustyButTrusty]

I also did the automatic transmission self test that is described in the FSM. The code came back as "Revolution sensor circuit is short-circuted or disconnected". Could this be causing my issue?

[Slartibartfast]

I don't know transmissions too well, but that sounds like a good place to start.

[Mr.510]

Sounds to me like it's either shifting in/out of overdrive or locking/unlocking the torque converter. Fixing the sensor problem will probably correct it.

 

The surging while decelerating down a long hill is pretty common on TBI trucks. Mine has been doing it occasionally for several years but only on long, steep descents when cold. It hasn't bugged me enough yet for me to bother fixing it. I think this is a completely separate issue from your transmission problem.

Edited November 12, 2011 by Mr.510