Slip Indicator Light

This subject came up in a thread yesterday too.

The slip indicator light comes on to alert the driver that the car is skidding, the front wheels are spinning (lost traction), or the ABS Anti-lock brake system is operating.

It's meant to warn the driver to simply be cautious about the current driving condition.
Realistically, it's an idiot light, because by the time it comes on the event is past, or deep in progress, and a light won't make any difference in the outcome.

Sounds like one of your tires lost traction when you went over the bump, I imagine.

All of this is a function of the VSC nowdays.

 

Like 9G said, all of your wheels were not moving at the same speed. Bumps can do it, slick roads can do it, rail crossings can do it. Just your car saying, "Watch it, bud, it's slippery!"

 

<div class='quotetop'>QUOTE(Boink @ Jul 19 2007, 08:22 PM) [snapback]481907[/snapback]</div>

yea happens to me all the time as well

 

Hi Boink,

Most likely you have become used to your Prius now. And are not afraid to use a little more pedal on accelleration. If you run across a damp or loose man-hole cover, bump, or slick rail road rail, the tire(s) slip.

Believe it or not, at lower speeds your driving a car with more torque than the tires can handle. Somewhat different than other cars And you need to keep your eyes open for poorer road conditions, and pull back the throttle over them. Something the old Porshe and Corvertte drivers probably do instintively, to avoid side stepping. But standard car drivers just do not ever have to worry about, as their cars just do not have the torque to cause a problem.

 

The loss of traction while going over a bump (and having the Traction Control activated and reducing power) has been discussed several times in the past year. It's normal. Just the Prius system trying to make sure the system components aren't damaged (MG1 in particular).

That you only saw the light and didn't feel a loss of power indicates you are just barely at the threshold.

 

Super old thread, hopefully someone can help. My slip indicator light has begun to flash consistently over 50mph and doesn't stop until i get down to 25 mph. I can go over 50mph with any trouble until there's a turn that takes me down to half my speed my car begins to rev rather than go. I just got new tires, not sure if it's a side effect. Any help is greatly appreciated!

 

I had a similar issue when I replaced my front tires with 205's when the rear still had 195's (and iirc 55 vs 65). The total circumference was too different and caused the traction control to interfere above 100km/h (in my case, ~65mph). Fixed it by ordering same size rear tires.
Right now I am having yet again a similar issue (cruise control switching OFF whenever hitting any minute bump or ridge) which *might* be related to really worn rear tires, even though rear and front are both 205's and same height. Rears are Michelin Energysavers that came with little thread to start with when new anyway iirc, fronts are Michelin Primacy's that have way better traction in the wet (my opinion) and are overall rated similarly (wear, fuelefficiency, noise, etc according to European tests).

If you changed all four tires, obviously check if they are the same size. If they are, chances are something went wrong when fitting them (ABS sensor not seated properly, wiring under stress, reluctor-ring damaged, etc.)

 

slip indicator light comes on when driving 20 m/p/h and breaking real hard..is that ok?

 

If braking hard means causing wheels to lock, then ABS SHOULD interfere. Not sure if this also causes the 'slip' light to come on.

 

Just read the following in section B12 Brake Control in Service Manual:
SLIP indicator Informs driver that Enhanced VSC and ABS are operating by blinking
light...".

 

I've noticed this as well if I hit a small bump/imperfection in the road while going 65 - 75 mph on the highway. Does anyone think a roof spoiler or a rear spoiler lip kit might help to reduce aerodynamic lift and thus prevent slippage? Does anyone put any stock into lip kits for aerodynamic performance (keeping mpg high & traction solid)?

 

I would first look at condition of the tire, springs, and struts. You see the "slip" indicator because the ABS ecu sensed one of the wheel speed sensors showing a (large) difference from the others. Unless a speed sensor is acting up and misreporting, then a tire had to come off the ground when you hit that "little bump".

Might also want to check the brake switch adjustment- I don't know if the ecu might trigger a "false ABS" event if it sees the brake switch active when going over a bump at high speed.

This is where having Techstream could be useful. It has records of what triggered the last several ABS - T/C events.

So short form- I don't expect an aero kit to do much as this shouldn't happen in most normal situations. (Braking or hard accel over a deep pothole or over a manhole cover is another story).

Posted via the PriusChat mobile app.

 

My 2004 Prius had a front flat, so I mounted the donut spare provided, and was driving to get a replacement tire, when this slip indicator light began showing, and the drive shifted into some new mode. I drove home, and checked the Chat, so thanks to those who posted about different tire sizes confusing the sensors. Used spare car to get new tire mounted.

 

You can disengage traction control so that you can go faster than 30mph. Plenty of videos on YouTube showing the steps.

 

This is not advisable. There is too much potential to do damage to the drive train.

To avoid this situation you should always mount the donut spare on one of the rear axles. Unfortunately, this means that you have to do two "remove and replace" wheel operations if you have a flat tire on one of the front axles.