Ls Tranny Dropping Out Of Od When Applying Brakes

[eatingupblacktop]

Has anyone experienced the problem i'm having with my 91ls?

At highways speeds, driving in overdrive, when I apply the brakes even slightly, the tranny immediately drops into third with the higher rpm and the reverse gear lights up in the dash. When I get off the brake pedal, the tranny goes back up into overdrive. I noticed my backup lights are not lighting up when I shift into reverse and the rear bulb indicator is lit up. The reverse gear lights up anytime I step on the brake, whether I'm moving or in park. Acceleration and shifting while driving is otherwise normal. It's very strange to see Reverse light up at the same as Drive whenever I step on the brakes. Any ideas?

[Leadfoot]

Has anyone experienced the problem i'm having with my 91ls?

Fortunately quite a few people have had this problem, do a forum search on the classic "trunk wiring loom was made too short" fault, where the wiring has worn through due to use and causes a backfeed of voltage that gives your symptoms. You should be in for an easy fix.

Cheers!

[eatingupblacktop]

Has anyone experienced the problem i'm having with my 91ls?

Fortunately quite a few people have had this problem, do a forum search on the classic "trunk wiring loom was made too short" fault, where the wiring has worn through due to use and causes a backfeed of voltage that gives your symptoms. You should be in for an easy fix.

Cheers!

Thanks for the info, any threads you can point to?

[Leadfoot]

Thanks for the info, any threads you can point to?

http://us.lexusownersclub.com/forums/index...+wiring+harness

[eatingupblacktop]

Thanks for the info, any threads you can point to?

http://us.lexusownersclub.com/forums/index...+wiring+harness

Sure enough, found the problem. Fixed it myself. Saved whatever the shop would have charged to "find" the problem. Thanks for your help.

[kenika65]

I experiencing all of the same problems as you.

I am hoping you can show me exactly where you found the wire problem and if that is all you had to do to fix the problem.

I have taken the trunk and back seat out and cant find any bad wires but maby im not looking in the right place pleas help me my car wont stay in od or it seems like it wont stay in od. thanks for all the help

[nc211]

I experiencing all of the same problems as you.

I am hoping you can show me exactly where you found the wire problem and if that is all you had to do to fix the problem.

I have taken the trunk and back seat out and cant find any bad wires but maby im not looking in the right place pleas help me my car wont stay in od or it seems like it wont stay in od. thanks for all the help

You don't have to take the seats out. Just open the trunk and look along the hinges. I can't recall which side, but you should see some wires around one of them. That's the area where 99% of the wire problems exist. Find the bad wire, reconnect it and tape it up with some electrical tape, or heat-wrap tubing.

[eatingupblacktop]

I experiencing all of the same problems as you.

I am hoping you can show me exactly where you found the wire problem and if that is all you had to do to fix the problem.

I have taken the trunk and back seat out and cant find any bad wires but maby im not looking in the right place pleas help me my car wont stay in od or it seems like it wont stay in od. thanks for all the help

Exactly as NC has described it. Driver's side hinge. BTW while you've got the back seat out, why not put in some additional sound insulation.