Vsc Out Of Control (too Sensitive?)

[r_ls400]

1999 LS400 with 85K miles on it. The road was wet after some light showers.

The car swayed bit time when I almost completed a U-turn. A beeping sound was on for that 2 to 3-second duration. I didn't have the leisure of checking the warning lights then. Parked the car, checked the tires, things looked OK, tires are in the middle of their useful lives, drove around the parking lot without noticeable issue.

Went out to the street and drove in an alerted mode, the car wobbled and swayed toward the lane to the right and back at the end of the first left turn after signal. It was a good thing that there wasn't any car in that lane. The car behind me must be scared and kept back. I immediately turned off VSC and proceeded home since I was only blocks away.

The VSC acted before on very wet conditions (with standing waters) when I stopped and went straight. I thought the VSC was too sensitive at those times.

Is this just the VSC and something else (power steering?)?

Is turning off VSC the right thing to do and is the car safe to drive under this condition? I am not much of DIYer and don't have the scanner to scan the error code.

Please help. Thank you.

[amcdonal86]

Turning off VSC should be a safe way to drive until you can get it fixed. Heck, plenty of LS400s don't even have VSC!

Why don't you go drive around and see if you can't replicate the problem and find out under exactly what conditions it occurs.

[r_ls400]

Turning off VSC should be a safe way to drive until you can get it fixed. Heck, plenty of LS400s don't even have VSC!

Why don't you go drive around and see if you can't replicate the problem and find out under exactly what conditions it occurs.

That's what I had been doing since the last message. I drove around the empty streets and made sharp turns with and w/o VSC. So far, I cannot reproduce the problem. The road surface has partially dried up since the last shower.

The rear wheel alignment is a bit off as I can see from the wear on the edges. Can the combination of wet surface and bad alignment trigger the VSC? I wasn't driving aggressively when it first happened, especially in the left turn the 2nd time. Just wonder if anyone has any similar experience. I was driving the car in snowy and wet condition just 2 months ago and nothing like this happened. It was a good shock in both times.

[PureDrifter]

Turning off VSC should be a safe way to drive until you can get it fixed. Heck, plenty of LS400s don't even have VSC!

Why don't you go drive around and see if you can't replicate the problem and find out under exactly what conditions it occurs.

That's what I had been doing since the last message. I drove around the empty streets and made sharp turns with and w/o VSC. So far, I cannot reproduce the problem. The road surface has partially dried up since the last shower.

The rear wheel alignment is a bit off as I can see from the wear on the edges. Can the combination of wet surface and bad alignment trigger the VSC? I wasn't driving aggressively when it first happened, especially in the left turn the 2nd time. Just wonder if anyone has any similar experience. I was driving the car in snowy and wet condition just 2 months ago and nothing like this happened. It was a good shock in both times.

vsc will trigger when it senses that one of the wheels is not spinning at the same speed (within a percent error) of the rest. bad alignment, possibly bad/dead shocks, old tires, and especially wet conditions can all by themselves cause you to lose traction.

you said you felt the car "swaying", i would get the suspension looked into. the VSC is much smarter than the TRAC system of previous LS' and doesnt misbehave nearly as often.

oh, and '98-00 LS400s had VSC as standard, it was NOT an option.

[r_ls400]

Thanks. I'll have the items checked even though the car is doing fine on dry surface. The car was also doing fine in my entire trip to lunch 2 hours prior, when it was raining. It's the unpredictability I have to deal with here.

How long does a wheel shock usually last? I don't quite recall if I have replaced the shocks before. I need to be more organized in my service record. Memory fades away fast.

[PureDrifter]

Thanks. I'll have the items checked even though the car is doing fine on dry surface. The car was also doing fine in my entire trip to lunch 2 hours prior, when it was raining. It's the unpredictability I have to deal with here.

How long does a wheel shock usually last? I don't quite recall if I have replaced the shocks before. I need to be more organized in my service record. Memory fades away fast.

varies 75-115k miles.

[SKperformance]

It has to do with one wheel loosing traction but can also come from the alignment of 1 wheel being off causing a yaw sensor to kick in . it can happen more on wet roads as it has the power to pull the one corner easier.

My rear right wheels toe is off and on slippery surfaces i can feel it pull the back end to the right and makes vsc kick in easy on wet.

[amcdonal86]

oh, and '98-00 LS400s had VSC as standard, it was NOT an option.

I don't disagree with you there. My point was that it's not unsafe to drive with VSC off.

BTW, I would be very surprised if your shocks are bad if the car has only 85k miles!

[r_ls400]

oh, and '98-00 LS400s had VSC as standard, it was NOT an option.

I don't disagree with you there. My point was that it's not unsafe to drive with VSC off.

BTW, I would be very surprised if your shocks are bad if the car has only 85k miles!

Took the car back from the shop after lunch. Did a tire rotation and the better pair is now in the rear. Since the wheel alignment includes a "thorough" inspection on suspension system, I didn't specifically ask for any particular checking. This shop has been very aggressive in asking for extra work in the past and this is what I need this time. The result is the rear right wheel was the bad one, per the tech. Toe was 0.27 (range 0.00 to 0.20 degree) and was brought back to 0.11. The other three were off in some areas but not too much. Hope the rotation and the alignment work will put the right amount of traction back in wet condition.

The budget crisis and pot holes on the California roads are giving a lot of alignment busienss to the shop folks.

Thanks again for all the help.