Hi .... I have a 1999 LS 400, which I bought used (about 2 years ago) with about 40,000 miles on it. I have had numerous problems with it at very slow speeds...1) it accelerates very aggresively when I push accelerator when going very slowly...sometimes almost dangerously so, 2) When on a steep hill, backing up slowly (like backing into a parking spot) the car jumps rather than accelerating smoothly, 3) When backing out of a parking spot, the car seems to stutter rather than smoothly, 4) When going very slow (I drive with two feet) and I have one foot on the brake and one on the accelerator (ever so lightly) there is often a decided "clunk"....so badly the first couple of times it happened I thought I had been rear ended. Lexus has put in two new transmissions...to no avail...and now they tell me these "quirks" are the nature of the brute. I'm going to Arbitration with them next Tuesday and was wondering if anyone else has experienced these (or similar) problems. I had a 1992 LS 400 up until I bought this one....and loved everything about it....including the service.....but now I'm a very disappointed Lexus owner....Bob

 

its just different since this was the first generation of LS (98-00) which used a Throttle-By-Wire instead of a regular throttle cable. waht u could try is disconnecting the battery for 10-20 mins (reseting ECU) and hope the steering comp will tone it down a bit. i had the same problem when i tried driving my dad's '00 LS400 but he could drive it smooth as hell. its just a matter of practice and learning to be very sensitive on the throttle.

 

Welcome to CL.

I'd reset the ECU's, either by pulling the fuses in the engine bay or disconnecting the neg battery cable for 30 seconds or longer.

This clunk...can you determine whre on the car it seems to originate?

 

I also have a clunk, mainly when I am braking from about 40 and the wheel cut slightly to the left. It seems to be comming from the left front.

 

If this is the infamous front clunk, it can be one of several componets in the front suspension. Strut/caster bars, upper or lower ball joints, upper or lower control arm bushings. It varies with each car what is worn however the most common is the strut bars. These strut bars seem to give signs from 60K-120K miles. Mine started at 60K miles. Have your trusted mechanic inspect the strut bar bushigns for cracking or excessive wear.

IMO, this front suspension feels great but is not as robust as it might be. Granted, the roads in So. Cal don't help with the pot hole infested craters I have to steer around or get stuck driving over.

Mine has developed a metal on metal squeak and clunk coming high on the right. Me thinks I'm looking at an upper control arm.

 

I've heard mine twice, but this has been over a week so maybe it didn't mean much. There are quite a few pot holes around here as well, but mainly on thereal twisty roads.

 

The jerking you speak off when driving off from a stop, or semi stop is something we have to live with. No one can correct it, because its a software error, and I dont know anyone who can reprogram it for us.

Software glitch: 1 Lexus: 5054.

 

So this "drive by wire" was introduced on the '98+?

The '04 LS seemed seamless during my drive. Also didn't notice it on an '00 but given I'm not driving these day-in-out to tell.

 

The 98's didnt have drive by wire. It was introduced in 2001. The 98's have a different system for the SNOW operation feature.