Slip Indicator issue while on highway

[aaron9252]

Hi All,

I tried doing a little research on this issue but found minimal info. Hopefully the experts can weigh in here.

While traveling on a 3 hour trip from my hometown back to where I currently live in my 2000 LC, I was taking a right-hand curve at about 68 MPH on the highway when all of a sudden the Slip Indicator light turned on, the vehicle jerked really hard and brakes started to apply. Scared the crap out of me but I was able to hold it still without issue. Within seconds, the vehicle returned to 'normal' and I continued to travel. Within about 50 miles, I was taking another right-hand curve at around 60 MPH and the exact same issue occurred.

This time I pulled over, read for a few online and decided to continue home since at that point I was out of the mountains on straighter terrain.

Obviously, I need to get something reviewed but before I take my LC to a Toyota dealership, I'd like to obtain some info so I'm not charged a rediculous amount, If possible.

Thanks for your help!
Aaron

 

[KlausVanWinkle]

Are you talking about the VSC indicator coming on and the beeping? Mine did that to me on windy canyon roads after off roading. I think I was just taking the turns too fast.

 

[OregonLC]

Any other details? Wet? Lifted truck? Gravel on road? What were the corners posted at? 45? 50?

The VSC system is pretty robust. Unless there is a wheel sensor failure I've not seen a negative experience posted here. And a bad wheel sensor results in dash lights.

The only time mine has come on is when I'm driving like an asshat in a 3T lifted truck.

 

[LCAdvocate]

Had a similar thing happen with my rig - VSC/TRAC lights came on, hard braking/wheel lock, while in a curve on dry pavement. Speed the first two times was 40ish, third 25/30mph. It happened 3 times over a couple of days of mountain driving. My rig is a 2002, OME lifted, and diff drop. Posted on it and guys talked about dirty sensors, etc, ..... It ended up being a front diff pinion bearing that was on it's way out. It was the bearing failure and the melting that caused the wheel to lock. There were two possible causes for the bearing failure, one of which is much more likely than the other. It was either the pinion angle change, post lift, which caused a slightly different fluid level and resulted in not enough oil slinging on the bearing, or the more likely scenario, the Toyota dealer over greasing my front driveshaft during the last service, which was 4/5 months prior to the trip. The guys that installed my lift should have probably checked the diff fluid after the install, but didn't and neither did I. Either way, the bearing finally failed and I decided to rebuild and regear. That of course opened another can of worms with driveline vibartions, post regear, but I haven't had any dash lights or wheel locks since.

 

[aaron9252]

Klause - not the VSC, but the slip indicator. It's the light on your dash that looks like a vehicle sliding.

Oregon- I was on interstate 40. Good conditions except for high winds. Curves were not posted as they weren't extreme. I could honestly say I might have been going 5-10 MPH too fast but nothing very unsafe. Just a few over the speed limit. My vehicle is all stock.

My fear is that the LC is my wife's car and I don't want the same thin happening to her. But I also am hesitant to quickly run to the dealer and have to get the credit card out due to cost.
I'll be driving it until fixed.

LCadvocate- so are you also suggesting the 'sensor' might be dirty? What sensor? Thanks.

 

[LCAdvocate]

LCadvocate- so are you also suggesting the 'sensor' might be dirty? What sensor? Thanks.[/QUOTE]

Not really, but it is always a possibility that you could have a faulty or dirty sensor. I'm saying that when I posted my issue several guys pointed to the same thing, dirty wheel sensors. That didn't really make sense to me. Why would such an important sensor, in such an exposed location, be prone to malfunction by dirt and moisture? Of course, Toyota could have botched the design, but that problem would have reared it's head in more vehicles than just ours and the design would have been changed or the problem recalled.

The failing bearing in my diff was causing a slight speed difference between the front wheels and that coupled with the bearing seizing was causing the the wheel to lock, the Trac light to activate, and the braking/locking of the front wheel.

Again, this is what happened to my rig.

 

[OregonLC]

Klause - not the VSC, but the slip indicator. It's the light on your dash that looks like a vehicle sliding

It's the same thing. ABS, ATRAC, VSC all operate off the same sensors/module.

LCadvocate- so are you also suggesting the 'sensor' might be dirty? What sensor? Thanks.

It's really the ABS sensor at the hub. ATRAC and VSC also use this data to determine what actions to take. VSC adds the input of a yaw sensor mounted below the center console. Other brands have used these sensors as TMPS. Again, a bad sensor should be showing up with VSC/TRAC lights on the dash. I'm more inclined to think there was some contamination of the road surface or there's something else going on mechanically.

A good test would be to find a curvy (or wide) gravel road. At about 30 mph make some hard turns and see if the system intervenes. If so, all is well. This takes skill, confidence, and knowing your vehicle's limits so only try if you have all three in spades. Very common for me to have happen cornering on washboard roads.

From the manual:

(m) Vehicle Stability Control System and
Active Traction Control System
Warning Light

This light warns that there is a problem
somewhere in the vehicle stability control
system and/or active traction control system.

 

[LCAdvocate]

It's the same thing. ABS, ATRAC, VSC all operate off the same sensors/module.



It's really the ABS sensor at the hub. ATRAC and VSC also use this data to determine what actions to take. VSC adds the input of a yaw sensor mounted below the center console. Other brands have used these sensors as TMPS. Again, a bad sensor should be showing up with VSC/TRAC lights on the dash. I'm more inclined to think there was some contamination of the road surface or there's something else going on mechanically.

A good test would be to find a curvy (or wide) gravel road. At about 30 mph make some hard turns and see if the system intervenes. If so, all is well. This takes skill, confidence, and knowing your vehicle's limits so only try if you have all three in spades. Very common for me to have happen cornering on washboard roads.

From the manual:

(m) Vehicle Stability Control System and
Active Traction Control System
Warning Light

This light warns that there is a problem
somewhere in the vehicle stability control
system and/or active traction control system.

Sounds like good advice to me.

Yes, it is an integrated system. In my case, the first time was similar to his experience - dash lights, hard braking, and nearly pulled me across the line while in a curve. The second time was lights, wheel lock for a split second while in a curve. The third was even worse and that's when the diff bomb went off in mine.

Here is my point and the question. Would the system with a dirty or faulty sensor completely lock a wheel while driving? That seems dangerous and counter to the system. If so, and it will lock a wheel due to a dirty or faulty sensor during mid to high speed driving, then that seems like a very dangerous situation and Toyota needs to be notified.

 

[OregonLC]

Are you sure VSC locked a single wheel or could it be that when the wheel mechanically locked due to a broken diff the system saw both brake application and a locked corner and went into full ABS which would be max breaking. Braking plus skidding to the computer could only be interpreted as needing intervention. If yaw matched steering angle then it would interpret as a skid.

Edit: To the OP. Just noticed that both happened in right-hand corners. So your right side was unweighted. I'll bet you have either a sicking caliper on the PS (right) or you have a rock or some other debris wedged in there causing one of those wheels to lock. If the former, I'll bet it's your right rear caliper. How is it for temp when you stop?

 

[marshotel]

I think the VSC system works by comparing the measured wheel speed of each of the four wheels as well as using information from accelerometers (yaw sensor), and the throttle position sensor. When the algorithim suggests that the vehicle is in a slide, it cuts the throttle and automatically applies brake force to selected wheels in order to correct the slide and get the vehicle pointed straight. For example, if you are turning left on an icy surface and the rear of the vehicle slides out to the right (oversteer), then the VSC system would cut the throttle and apply brakes at the right front and right rear wheels while making a repetitive beeping sound. This system, combined with ATRAC, worked great (and frequently) on my 2000; it probably kept me from the ditch several times while speeding around Anchorage in the snow, or going too fast on gravel roads.

Others, however, have not been so lucky with VSC:
https://forum.ih8mud.com/100-series-cruisers/339485-vsc-caused-me-total-my-lc-100-a.html

As long as the algorithm is good at deciding when a skid is occurring, then the system works great.
The problems seem to happen when you have a false-positive skid detection.

Erroneous wheel speed data- caused by crap on the wheel speed sensors, or mismatched tires - may result in false positive skid detection- consistent with the descrption in the original post. I think the wheel speed sensors involve magnetic detection. While the sensors are generally pretty robust, it is not hard to imagine how a really dirty magnet- for example covered in road tar and sand- could result in errors.

I think your best bet is to hit the wheels and brakes with a pressure washer- like at the coin-operated carwash, then do some testing in a safe area to get a feeling for how the system responds. Like Oregon said check your brakes for rocks and debris and stuck calipers; check your wheel speed sensors for gunk.

If it was a stuck caliper or other mechanical problem, I don't think the VSC would light-up. I would bet on dirty wheel speed sensors:

https://forum.ih8mud.com/100-series-cruisers/707488-traction-control-locking-front-left-wheel.html
https://forum.ih8mud.com/100-series...r-any-suggestions-where-get-one-cheapest.html

For me, VSC was great on ice and on fast gravel roads. It saved my a$$ more than a few times.

I am gonna have to be more careful now that I have a 1998 model without any of the VSC or ATRAC systems. it Powerslides with impunity!

 

[krnnerdboy]

From my experiences its always the tires(oversized, under inflated, worn) that cause vsc to act out of the ordinary. My fjc had the exact same thing you described when I was going through a canyon. It nearly pulled me into the opposing lane. I could get it to consistently do the same thing on long sweeping right turns. My fjc was on 33" MUDs Eventually I learned that slightly hovering over the brakes in those conditions would stop the vsc from interfering.

My 10 tundra had 35" MUDs and I couldn't accelerate past 70% throttle in a straight line without vsc kicking in. It was routine for me to turn the system off before leaving the parking lot....

My g500 is on 33's and the car would violently brake when cornering, until I reset the tire diameter parameters in the ecu. Stock size was 31.5"

 

[aaron9252]

Great info, darn near too much for my inexperience-of-the-VSC-brain to handle. I won't lie, i re-read the last few posts a few times.

What I'd like to do is try two tests:
1) Highway test since this was the original issue. I think I can find an area to do the test 'safely'. Mentally record environment - speed, weather conditions
2) I also know of a dirt road to test the VSC. Find a good spot to get the VSC to engage.

Then I'll clean the heck out of the sensor, wheel, and check for rocks, and any other obstructions.
Once I do that, I'll test the highway scene 1st then the dirt road situation.

Hopefully it's just a dirty sensor.

If it's not, is there a safe way to disengage the Slip Indicator/VSC? Again, this is my wifes vehicle and she's anti-rock climbing, snow driving, river crossing, and dirt road speeding so I don't think she'll miss it. Thoughts?

thanks!

 

[krnnerdboy]

There's a way to disable the vsc for damn near free(pin 7 mod?)but I would want vsc enabled for my wife to be honest. It's a great system but for whatever reason it gets confused at times. It's only happened a couple times on my fjc in the 2 years that I owned it. They just happen to always be on my way down a mountain...

Things i would do in this order....

Check air pressure
Check tire wear
Check alignment
Check/clean sensors
Bleed the brakes

 

[marshotel]

There are two ways that you can easily disengage the VSC, neither of which are ideal for daily driving on normal roads:

1) lock the center differential using the button on the dashboard just to the right of the climate controls, under the button for the hazard lights. Locking the center diff forces the front and rear driveshafts to spin at the same speed, and disables the skid control (VSC). [corrected: locking the center diff disables VSC, but does not affect ATRAC]. Consensus says that it is not a good idea to drive long distances with the center diff locked under normal driving conditions.

or

2) pull the fuse for the anti-lock braking system (ABS). Because the ABS and skid control rely on information from the same set of wheel speed sensors Disabling the ABS also turns off the VSC. Again, consensus says that disabling the anti-lock brakes on a 6000 lb. vehicle is probably not a good long-term solution for your wife's daily driver.

I would recommend:
1) check and clean wheel speed sensors
2) check brakes for debris and proper functioning

 

[TrekboxX]

Great info, darn near too much for my inexperience-of-the-VSC-brain to handle. I won't lie, i re-read the last few posts a few times.

What I'd like to do is try two tests:
1) Highway test since this was the original issue. I think I can find an area to do the test 'safely'. Mentally record environment - speed, weather conditions
2) I also know of a dirt road to test the VSC. Find a good spot to get the VSC to engage.

Then I'll clean the heck out of the sensor, wheel, and check for rocks, and any other obstructions.
Once I do that, I'll test the highway scene 1st then the dirt road situation.

Hopefully it's just a dirty sensor.

If it's not, is there a safe way to disengage the Slip Indicator/VSC? Again, this is my wifes vehicle and she's anti-rock climbing, snow driving, river crossing, and dirt road speeding so I don't think she'll miss it. Thoughts?

thanks!

You should NOT disable the VSC, especially if your wife isn't "into" that stuff. The VSC could very well save her life in a panic skid situation. Fix whatever problem you have, don't cover it up.

There are two ways that you can easily disengage the VSC, neither of which are ideal for daily driving on normal roads:

1) lock the center differential using the button on the dashboard just to the right of the climate controls, under the button for the hazard lights. Locking the center diff forces the front and rear driveshafts to spin at the same speed, and disables the ATRAC and skid control (VSC). Consensus says that it is not a good idea to drive long distances with the center diff locked under normal driving conditions.

or

2) pull the fuse for the anti-lock braking system (ABS). Because the ABS and skid control rely on information from the same set of wheel speed sensors Disabling the ABS also turns off the VSC. Again, consensus says that disabling the anti-lock brakes on a 6000 lb. vehicle is probably not a good long-term solution for your wife's daily driver.

I would recommend:
1) check and clean wheel speed sensors
2) check brakes for debris and proper functioning

Locking the center diff does not disable ATRAC. That's when you need it- when you're locked and trudging through the crud.

 

[TrekboxX]

Oh- and you shouldn't drive at all under normal conditions with the diff locked...

 

[echobravoecho]

I'll add my experience, albeit late, to your issue.

Errant activation of the skid control system can be a symptom of a worn out or wearing out steering rack.

My ride, 2001 LX470, 95K miles, had the same symptoms. Sweeping left turns on the interstate caused the beeper and lights to go off, after which the right front caliper would lock up and violently throw the vehicle to the right. The instances of lockup steady increased and got worse as the weeks went by. Then sweeping right turns would cause the lockup. Since this was a life threatening situation, I disabled the system by unplugging the three wire ABS cable from the bottom of the brake master cylinder. This was the simplest and easiest action to take as I didn't have to crawl under the truck and short the 4wheel drive sensor in the transmission. When I needed 4 wheel drive I'd just open the hood and plug the cable back into the master cylinder, and wheel away with the system working fine. Since I learned to drive on non-ABS vehicles, disabling it did not concern me.

Then I read all I could about dirty sensors, mismatched tires, bad driving behavior, high dealer cost, recalibrating the steering wheel, etc. Over the span of a few weeks I realized that my problem was not faulty sensors, but rather something that was wearing out over time and getting worse. Sure enough, with the skid control system disabled, I was able to discern that the steering rack was getting sloppy and required replacement. I also did the upper and lower ball joints, as well as the rack bushings and control arm bushings. All nice and tight now, and no more skid control problems. This vehicle still has mismatched/worn out tires, out of balance tires, out of alignment, steering wheel turned a little, and the skid control does not go off after the steering rack replacement.

Hope this helps.

 

[Greenbean]

I want to bump this as on my way home tonight from Chatlotte all of a sudden I get a warning buzzer and the slip indicator light is flashing, at 70 MPH on the interstate. Wife was on the phone with me and heard the beeping. Mechanically and driving wise the rig didn't feel at all odd. It's very smooth. If I could remember anything I think it was maybe a slight left curve in the highway. Not enough to where people are braking though.
I slowed a bit and it flashed and beeped for Maybe 10 seconds and then stopped.

Then over and hour later after coming up Saluda grade cruise control is on and I'm in a left sweeping curve and all of a sudden the rig lunges right then left, all the while the skid control light is flashing and beeping.

The only light in the dash was the slip control light,

Odd thing too is about 4-5 times on the way home the cruise would cut off on its own and I think it was when the transmission might have been wanting to downshift but I'm not sure.

I'm going to check all the wheel speed sensors tomorrow and see if I can clean them. I'll take some pics also before I clean them. Also I am hopefully going to dive into the FSMs I have coming, UPS should be delivering them to me tomorrow.

I also think my rack is leaking a bit, so I'll have a look there too.


BTW, rig is a 2000 LC stock susp, Nov evening @60ish degrees outside and oh I have 436K on it too.
Going to also dive into the service records I have and see if I see anything in the way of that complaint and/or repair.

Honestly it was alarming enough for me that until I sort it out my wife isn't driving it.
It has got to be something obvious when you think about the symptoms.

Faulty wheel speed sensor... Straight direction of travel, I hear beeper and see light flashing...
Faulty wheel speed sensor... Curved path of travel, ECU thinks I'm out of control seeing steering angle changing and wheel sensor says it's slipping...

 

[haas]

YUP! I just went through this a few weeks ago on my 2000 LX470. Exact same symptoms. Hooked up Techstream while driving and I couldn't find a thing on the sensors. I even tried cleaning the ABS speed sensors....went down all sorts of rabbit trails. I almost replaced the several hundred dollar steering wheel sensor.

Glad I didn't.

It was the steering rack bushings. $45 for the whiteline set on amazon.com. Great write-up on the bushing install somewhere on this forum. The last time I was in to the Toyota dealership, I talked to their shop foreman...he's seen the same thing before.

Basically your VSC goes off on the freeway while you're on a slight curve on the highway...Mine kept getting more and more frequent. I couldn't drive a few miles down the highway without it freaking out (granted I live in the mountains and the highway has quite a few twists). It was terrifying. I've put on about 1,000 miles since replacing the steering rack bushings and not one issue.

Worked for me!

 

[Greenbean]

Appreciate that boss,

I may put the front on jack stands first and pull the bash plates and check them first.

I can also say I have noticed in left turns it's smooth as usual until you run over an expansion joint and then you almost get a death wobble...

Is will be interesting....

Stay tuned folks!