Slip indicator on dry roads

[mac33]

Hello everyone, I just purchased a 2001 4x4 Limited and while driving home cruising at like 70mph 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. Could someone point me in the right direction on why this happened?

I did some research and a lot of threads say to make a switch to to turn ABS/ASC off or pull ABS fuse?

Truck is stock with no CEL or any other lights on @ 145k. I have not driven it since to tell if this is an ongoing issue.

Looks like this (not my video)
https://www.youtube.com/watch?v=udRdRYPdZ9M

 

[WeAreSLO]

You were driving in a straight line? That would be really weird for the TRAC/VSC to kick in on a straight dry road.

 

[mac33]

It could have been a long sweeping left turn and I dont remember hitting any bumps as well.

 

[jgue467]

Slip indicator. Mine has only done the same on a dirt road where I went just a bit too fast during a long sweeping turn and began to slide ever so slightly to one side, the system recognizes the slip and begins to apply brakes and modulate engine output to control the slip/slide.

So either the vehicle truely experienced the slide or a mistake was made due to ill-performing parts of the system, could be a wheel speed indicator, wiring or the related ECU.

I'd try the same path again and study it better to determine better whats going on.

Usually you hear of these odd issues when taking off from a standing start during slippery snow or icy conditions or like mine, dirt road.

Luck and enjoy the Runner. :cowboy:

 

[mac33]

Drove the car some more and it happened twice, luckily it was just the slip indicator and beeping -no ABS activating this time.

1st occurrence - slowing down for toll slowing down from 60mph slight sweeping

2nd occurrence - going 65mph long right sweeping turn


Any ideas?

 

[mac33]

Slip indicator. Mine has only done the same on a dirt road where I went just a bit too fast during a long sweeping turn and began to slide ever so slightly to one side, the system recognizes the slip and begins to apply brakes and modulate engine output to control the slip/slide.

So either the vehicle truely experienced the slide or a mistake was made due to ill-performing parts of the system, could be a wheel speed indicator, wiring or the related ECU.

I'd try the same path again and study it better to determine better whats going on.

Usually you hear of these odd issues when taking off from a standing start during slippery snow or icy conditions or like mine, dirt road.

Luck and enjoy the Runner. :cowboy:

Thanks for the input, ill look into the speed indicator. I cant wait to drive it more

 

[mac33]

We'll I did some more research and I came across this thread.

3rd Gen Yaw Calibration
01-02 4Runner How to Zero Point Calibrate your VSC system. - Page 2 - YotaTech Forums

Going to try re calibrating the YAW sensor, will update this thread for future research purposes..


This is the procedure for calibrating the yaw sensor:
1. Open the DLC-1 diagnostic port on the driver side in the engine compartment
2. Turn the ignition on
3. Using the jumper wire connect the E1 and TS pins 4 time or more within a 8 second period
4. Check that the VSC TRAC light on the dash came on again, it should be on for several seconds and then go out
5. Turn the ignition off
6. Wait a few seconds, then turn on the ignition and wait for the VSC TRAC light to go out

This is the procedure for calibrating the deceleration sensor:
1. Connect terminals E1 and TS again on the DLC-1 diagnostic port
2. Turn the ignition on
3. Check that the VSC TRAC light is on for about 4 secs and then starts blinking at 0.13 sec intervals
4. After the light has been blinking for 2 secs turn the ignition off
5. Remove the jumper wire




If anyone else has any other ideas feel free to share the knowledge. I will be driving this truck 90 miles 5 days a week so I want to be as safe as possible. :high5:

 

[OrRunner]

We'll I did some more research and I came across this thread.

3rd Gen Yaw Calibration

Going to try re calibrating the YAW sensor, will update this thread for future research purposes..


If anyone else has any other ideas feel free to share the knowledge. I will be driving this truck 90 miles 5 days a week so I want to be as safe as possible. :high5:

In my experience the VSC system is quite sensitive to rear end sway, and a sweeping, higher speed turn is likely to set it off. Inspect the rear suspension for worn components such as worn or broken sway bar end links and leaking shocks. If the rear suspension looks good perform the zero point calibration and retest the concern.

 

[mac33]

In my experience the VSC system is quite sensitive to rear end sway, and a sweeping, higher speed turn is likely to set it off. Inspect the rear suspension for worn components such as worn or broken sway bar end links and leaking shocks. If the rear suspension looks good perform the zero point calibration and retest the concern.

All rear suspension parts seem to be fine to the eye and rear shocks do not seem to be shot.



UPDATE:
I overlooked it all, it could be just low tire pressure. The passenger side front had 10psi, didnt look like it though haha. Pumped it back up and so far so good. :clap2:

 

[jgue467]

...
UPDATE:
I overlooked it all, it could be just low tire pressure. The passenger side front had 10psi, didnt look like it though haha. Pumped it back up and so far so good. :clap2:

Well one tire being a different Size (due to low inflation) would make a diff especially on a long turn.

You Really need to add "Check Air Pressure" (+spare) to your T'o Do' list like at least once a month and especially when the seasons change....many a folk have encountered far worse results than a slip indicator.....

Luck and enjoy the Runner. :cowboy: