4 runner autotrans overdrive problem!!!

[crash51]

ok here the problem i have with my 1990 4runner 4x4 3.0 v6 auto with overdrive

what happens is when i ingage the overdrive it fails to shift over, how ever when i first bought this truck it did work for a short time, like in town & freeway, but it often down shifted back to 3 gear, now it fails to go in overdrive all together????? the trans works fine no slipage or any thing elese funny going on ..??? the fluid is good no leaks ,the overdrive light does come on. so maby you guy might know what is going on here, i cant say that a new trans warents this problem


MaRk:-)~

[Brian R.]

Might be your engine thermostat. Engine temperatures affect shift points.

[All Engine]

Have you checked to see if it has any codes?

High resistance of the E-17 ground splice can cause your problem too. You would need to check the E-17 splice to see if it is sodered on or if it has the crimp connector. If it is the crimp type of connector just clean it up and soder the wire on to eliminate the crimp connector. You should find it located in the junction behind the water pump reservoir. It can be reached without moving anything.

Keep us posted on how it goes.

[Tomsriv]

I had that problem on another car and it was just a simple relay under that dash. The relay had a circuit board inside with worn solder from 17 years of hot/cold cycles. I carefully resoldered it and it works fine.

Its funny, in the 80's car companies began to switch over heavily to electronic components because they were thought to be more trouble free than mechanical components. However, in my experience it has been the electrical problems that show up first and are the most likely to make an owner junk their car.