Vsc/engine Lights, No Power

[handygal]

Dumb, dumb, dumb.

I have a '98 LS 400 , 55K miles.

About 4 months ago my VSC light came on and wouldn't shut off. After turning the engine on and off a few times, giving up and going inside and a few calls to my husband, the mystery light went away. I didn't have the code read, I considered it a fluke.

In the last few months I have noticed onboard computer resetting as if it thinks I stopped for fuel. i.e. I filled up 2 nights ago and have driven approx. 70 miles, but the car now says 13 miles since last refuel. This has been happening slightly more frequently. I had attributed it to parking on a slant or going up a steeper slope but that hasn't been the case this week.

So today was the kicker. I drove home about 10 miles, mostly highway. Shortly thereafter I made a quick trip. After an hour I headed back. I put the car in drive, rolled out of my spot, pressed the accelerator, nothing. I put the car in neutral, checked all around, checked if the floor mat had crept up under the pedal, nothing. Shifted to drive. Nothing. Car is still idling at 700RPM and rolling. I floor it. Nothing. Press down about half way and release a few times. Pedal feels like mush. All of a sudden, we have contact. OK, so I settle in my seat, car feels fine, I head home.

I'm cruising around the neighborhood, stop at a few stop signs, no problems. I slow to take a sharp corner, step on the accelerator and nothing again. I press harder, the car goes suddenly, backs off, goes. The VSC and engine lights come on. This is a fun ride. I'm in the neighborhood so I take the quietest road, turn on the hazards and let it roll most of the way to the babysitter's. I put the car in park and it revs to 1400rpm. I try starting and stopping the engine, removing the key in between to see if I can get the error to cycle out.

I drive the few blocks to my own house in a mix of rolling and driving normally. After coasting or stopping the car doesn't want to go. Keeping my foot on the accelerator will get the car going after about 10-15 seconds but only if I have it down pretty far and then the car takes off when it kicks in , of course. It scared the heck out of my toddler so I chose to roll the rest of the way.

Sorry for the long story but WHAT THE HECK IS THAT? The error lights are still on and the car will still idle up to 1500 RPM in park. It sounds like the VSC is engaging itself and one of the sensors for it has gone bad. But why will the car go again and why is the idle so fast in park? In drive it idles around 700-800. I suspect it's something else? I bought this from my mother, so I know the history and there is nothing but pretty regular maintenance. I will have it towed to the mechanic tomorrow but does anyone have any ideas?

[VMF]

well you have to get error codes and then it will be clear what is going on. just give us error codes and we will tell you how to troubleshoot the problem if your mechanic will not know. as of now its really hard to pinpoint the exact problem.

our car is OBDII compliant so it would be no problem to get codes from the car. just make sure your mechanic will get those codes out before doing any repairs.

your car is smart enuff to tell you what is wrong with it.

[JPI]

Looks like your TPS is going out. Get it check out though.

JPI

[handygal]

The lights are out and the system has reset. The car runs fine for today. I will drop it at the mechanic's tomorrow and let you know what the outcome is.

How I got the system to reset:

Tried every tip from every forum I read. Then I recalled someone mentioned a yaw sensor had gone bad on their car. So I opened the trunk, hopped in and jumped up and down. Then I rocked the car side to side. A few minutes of this and I tried starting the car again. Initially, all the same warnings came on but then cleared after 20 seconds. Car has been running beautifully today.

I appreciate the feedback and will be back with those codes!

[SW03ES]

Sounds like the throttle position sensor to me as well...

[blake918]

So I opened the trunk, hopped in and jumped up and down.  Then I rocked the car side to side.

Any of your neighbors get a video clip of this?? Just imagining someone hopping in to their trunk and jumping around makes me laugh histerically!

[VMF]

ROFL:)

i wanna c that too :D

[SKperformance]

I don't think it is a yaw sensor.You just gave your neibours somthing funny to laugh about. You used to be able to do that with older fords with a fuel cut out switch in the trunk but it usually ment just resetting since it was hardly ever in a case of a rollover.

It definatly sounds like the throttle position sensor. Don't try and rest the car without haveing the car codse read it will only lead to more trouble to diagnois

[handygal]

Too funny. I guess I can be glad it was 3 am. After driving around the neighborhood at 5 MPH, stopping, going, hanging my head out the window etc., jumping around in the the trunk might not have seemed so strange.

On that 3 am trip I did discover that it sounded like the front brakes where being dragged a bit so I still really suspect the VSC.

I'm not taking any chances on losing those codes, I just really needed the car to run today. I'm headed out of town and leaving the car at the mechanics tomorrow. I am really curious. One thing I've learned with cars, they often defy logic and the solution tends not to be what I expect.

[blake918]

I don't think you need to worry about losing the codes as long as you don't unplug your battery or lose power some other way. In my experience with check engine lights I've learned that if there really is a problem with the car, the computer will sense it over and over again even if you turn the light off some kind of way. I tried to get rid of my check engine light by pulling the battery. It would go off for a few days, and then, it would come right back to grace me with its presence! I finally figured out that a Vacuum Switch Valve was bad...it's some little gizmo that works with the egr valve. Replaced the VSV, and I haven't seen the cel since.

[VMF]

ECM logic is built on the 2 trip detection, so if it happens 2 times lights will come back and in ur case it will:)

[handygal]

I bow to the Lexus masters.

The only code in the system is P0121 - AKA - Throttle Position Sensor.

I am trying to recreate the problem to be sure we got all the codes before I start chasing it. Thanks for the help.