Dosn't shift when runing

what kind of car year make model

Hi there,

Some automatic vehicles rely on the brake switch (mounted on brake pedal) to be activated by depressing brake pedal. This signal then operates a relay and switch, to release the gear lever.

Firstly, I would check the brake pedal switch (are your brake lights working?).

If brake switch is confirmed OK, then inspect the relay (and related circuit components) of the gear release switch.

check all your fuses in engine compartment and under dashboard engine check light comes on every 3000 miles for oil change reminder

Could be a vac modulator problem.

Check the transmission fluid level, by the book, usually with the motor running in park or neutral, find out which one.
If that's ok, start looking for a bad vacuum line or connection. Any vacuum leak can throw off the transmission shifting. Try to pull each connection off, if it comes off easy, check to see if it is split or swollen. My Ford uses hard plastic vacuum lines, they break.

check to see if the vacuum line is hooked up to the modulator,(on the trans. next to the pan u will see a steel line with a vacuum hose on the end.
Make sure it has vacuum when running also ,if everything is ok,pull the hose off the modulator ,if any fluid comes out ,it's bad
Also if the governer gear stripps out ,same problem,under the round cover on the tailshaft,with a wire bail safty clip usually, just pop the wire clip pull the assembly out and look at the PLASTIC gear on the end ,if it is "applecored " it's the culprit.

Hi Ray, The advise above is good and should be checked out. If that does not solve the problem, before looking for a replacement transmission check and make sure the clutch is fully disengaging. If the clutch is mal adjusted that can also cause a problem with shifting gears. If the gears are stuck and wont shift at all the problem is most likely with the selector rods and/or forks. In that case you'll need major transmission work carried out. Regards John

replace the shift lock solenoid next to the shift cable inside the vehicle
A GM dealer item only I am afraid to tell you

If it starts out in 2nd gear & dosn't shift, it is probably in a limp in mode. the system will need to be diagnosed & computer satisfied. sometimes disconnecting the battery will reset the computer & allow the trans to shift untill it sees the problem again. I recomend getting the codes read first so the memory will not be erased.

my daewoo lanos wont shift into gear/s while running even when clutch is depressed all the way