1992 Ls400 Mystery Problem

[INDEFACE]

I have a 1992 LS400 which has been problem free for the 2 years I own it. Today a strange thing is happening. When I press the Brake pedal the R comes up on the dash. As in PRNDL indicating Reverse. It also results in a bang when going into Drive gear while pressing the Brake. When I shift to Nuetral and release the brake and then enter Drive it is fine and there is no bang. When I shift into Reverse the reverse lamps do not go on. I am not sure what the problem is. It could be the tranny, a fuse, a relay? I am not sure. Does anyone have a clue??

[obergc]

This almost sounds like similar electrical problems that were reported in the past and were corrected by repairing a broken ground wire in the left hindge area of the trunk. Check the wiring in the left hindge of the trunk, that's the first place I would look with a problem like yours.

[CUMan]

This sounds like it could be a broken wire in the wiring harness attached to the left trunk hinge. This is a very common problem on the first generation LS models, and it causes a wide array of weird problems. When I had a problem with this wire on my 93 LS, the "R" (reverse) light illuminated, my brakes had an odd feeling to them when applied, and my remote trunk release would not work.

Check all of these wires. If I recall correctly, the one usually involved is either white or white with a black stripe. Splice a new piece of wire in place if you find a broken wire.

[INDEFACE]

This sounds like it could be a broken wire in the wiring harness attached to the left trunk hinge.  This is a very common problem on the first generation LS models, and it causes a wide array of weird problems.  When I had a problem with this wire on my 93 LS, the "R" (reverse) light illuminated, my brakes had an odd feeling to them when applied, and my remote trunk release would not work.

Check all of these wires.  If I recall correctly, the one usually involved is either white or white with a black stripe.  Splice a new piece of wire in place if you find a broken wire.

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This makes sense. It started when I went to the trunk and returned a tool to the toolbox on the left side of the trunk. I will check it out. Thanks.

[GSsoldier]

HEY guys this problem just happened to me... it started after something in my car hit the shifter down to L on a turn... can anyone point out what i should do first i dont know where this wiring harness people are talking about thanks guys

[GSsoldier]

also just to add i think my brakes are terribly worn i washed my car like a couple weeks ago and the brake dust is growing faster then before

[90LS400Lexus]

They really need to have a recall on this matter. I have seen a LOT of owners reporting these bizarre electrical glitches over the years.

[leeelooo]

Your guys are Great!!!!!

This thread solved my 4 probelms at once:

-- 2 years ago, my Bulb-out Indicator was on every time when I 1st time press the Brake after started the car

-- 6 months ago, my driver side front brake became Not Smooth; made nosie when appling brake

-- last weekend, all the sudden, my trunck could not be released from release switch

-- last Monday, my transmisison can not be shiffed to up gear, after i turned lights on and then got "R"

After i read this, i checked my trunk hinge, YOU ARE RIGHT, there are 3 comlete broken wires, White, Yellow and White/black strip. Then after I reconnected them back all of above 4 problem fixed!!!

Many Thanks!!!

ps. my care is 93 LS400 with 129K miles. to me it is materal issue as those 3 wires are very hard while compare to normal wires....