1990 Ls400 Transmission

[1990LS400PA]

Im new to this forum but have found it very helpful. To the point: 90 Lexus LS 400 224,000 miles. Having problem with the transmission (im assuming). Anytime I touch the brake it feels like im getting rear ended. Also sometimes when Im driving - the car will be stuck in a certain gear. I have to exit the freeway several times because of this. Most of the time it gets stuck in 1st or 2nd gear. Would appreciate any help - I have dropped a lot of money into this ride already and Im real frustrated. Any help would be greatly appreciated.

I noticed this post earlier

I have the same problem but the problem only occurs at night time , when driving with the lights on. If I come to a complete stop and then begin to go again , I need to shut the lights off for the car to shift into third gear , once the car shifts it will continue to shift perfectly fine until I come to another complete stop. I then begin to drive shut the lights off and then turn the lights back on and its working perfectly fine. I do not know how the lights would have anything to do with the shifting of my transmission but any input or advice about this issue would be excellent.

Thank you

[dcfish]

Sounds like you are experiencing the trunk wire harness syndrom, There is a wire harness (I beleive it is in the drivers side hinge) The insulation on some of the wires wear off and create a short that causes all kinds of different electronic issues. Do a search for the trunk harness.

Welcome to the club

[steve2006]

Here you go

http://www.lexls.com/tutorials/lighting/bulbout.html

[VBdenny]

Before you go with all that, check the battery. If that is older than 3 years, go get a new monster for your LS. I recommend an Optima Red Top from Costco for $140 but anything with good CCA's (850+) would work. Not sure why but early ls's (mine is also a 90) suck juice big time. A battery can look good, test good and still not have enough for your car. If all this is cool, then the trunk wires broken would be my next move. I have fixed mine twice and both times the "R" light came on and the transmission wouldn't shift. Hope this helps a little.