toyota lucida

overdrive switch on auto gearbox not engageing any ideas please?:frown:

Any other warning lights flashing? Poor engine performance? Hard starting? Has the transmission fluid been checked or changed recently?

Post back with anything you find...the more clues the better.

Engine warning light has been on for the last three years had it checked by garage i got car from ad they said that all ok,oil change light, on but the performance is no different also battery is not very good so need to replace it.

A few more basic questions I should have asked:

1) Model year?
2) Engine type & size
3) Your location (country is enough)?

Did you have the engine light checked out three years ago or just recently? I ask because once it is on, it won't be able to let you know if more problems are detected (with the exception of a serious problem then it would flash). However, when it was checked, the mech should have reset the light by clearing all the trouble codes to see if it returns. First thing to do would be to go and ask what the specific trouble codes that have been stored in the vehicle's computer (or ECU) and clear them from the memory and post those here. Then if the light comes on again, you'll know what code is occurring now versus 3 years ago.

Typically, problems with older Toyota transmissions are relayed by flashing the "O/D OFF" light on the instrument panel. However, you don't mention the light being on. My first guess is a faulty temperature sensor or circuit, but usually the transmission won't upshift past 2nd or 3rd, not simply disable the O/D until the proper temperature is detected.

My second guess is the switch itself. If you use it alot, say for driving through very hilly terrain, then the contact may have become worn or oxidized.

I wouldn't wait to change the oil, and post back on what the transmission fluid looks and smells like...this is a good indicator of its condition. Red is good, pink is okay, brown and burned is bad.

Keep feeding info & we'll try to figure it out.

sorry taken so long to reply but computer crashed,does auto gearboxes have a relay switch? i wastold this could be the problem,had a look at the colour of the gearbox oil and it is a reddish colour,i took the car out on new years eve for about an hour to pick up my kids and it did not work untill i was 5 mins from home on return trip.

Most Toyotas have programming to prevent shifting into O/D until the engine coolant reaches a certain temperature. This is to help warm up cold transmission fluid (it is heated and cooled through a small heat exchanger inside the radiator).

The ECM monitors this via an engine coolant temperature (ECT) sensor. It is usually located in the metal neck where the upper radiator hose connects to. If it is not reading correctly or the electrical connector is loose or oxidized, the faulty info can cause the ECM to prevent O/D.
I suggest to find the sensor and check the contacts for corrosion/oxidation. Scrape the sensor contact clean with a small knife and remove/reinstall the connector repeatedly to help clean the connector contacts. Then recheck with a test drive.

If it still doesn't work, use a resistance test meter to test the sensor when cold and hot. Resistance should be high when cold (>10 kOhms) and low when hot (<1 kOhms).

Let us know how you fare...good luck!