transmission or TCU?

[Witam]

How can I check if it is the auto tanny or the TCU that is bad? My 240SX engine revs but does not move in all gears including reverse. Everything was fine coming off the freeway and all of a sudden it was like the transmission was thrown into neutral. The fluid level is good and the filter was replaced 2 years ago. How can I verify if the transmission is bad without taking it to a transmission shop?

[rogoman]

When the car fails to move in any gear, here's the probability of order starting from the most likely:1 - ATF level too low2 - control linkage problem3 - shift solenoid valve A malfunction4 - overrun clutch solenoid valve malfunction

There are more possibilities but the transmission must be removed from the car and disassembled.

Items #3 and #4 can be diagnosed by running the TCU self-diagnostic procedure to read the possible codes. If you have an FSM, the procedure is outlined there.