Orange dashlight flashes when releasing the throttle in the wet???

It depends on the tires for sure. The stock Goodyear Integrity's make the light flash even on dry pavement if you brake while going over a bump. Try accelerating harshly on wet roads from a dead stop and the light will come on big time as well as shut down power to the wheels. It will also light up if you corner sharply and go over a bump like leaving a parking lot and turning quickly while accerating heavily to get into traffic, even on dry pavement. The Prius Traction Control is very finicky. I would bet the light you are seeing is the light for the traction control system. It is automatic and always on. It cannot be turned off like some vehicles.

There is a lot of discussion on this board about the tires and traction control. Take some time to do a little research on both and then when you need tires make the change then. Other than that you simply have to accept that the light is part of the "nature of the beast".

Ron

 

What's your air pressures, tires, and tire sizes?

 

Different makes of tyres mixed front and rear or new and worn tread mix can make the traction control light flash at even a minute difference in wheel speeds or loss of road grip.

 

Could you please check the exact type of tyres fitted to the car and sizes eg are the Primacy's HP/ MXM4/ MXV4 and size 195/55/16 or 205/55/15 ect are the Energy savers just that or are they Energy saver AS, and again the size. Are the treads about the same front and rear or is one pair new and the other pair worn.

I know this may sound trivial but it is not.

John.

 

I agree with John (Britprius). The Prius can get real finicky at times and the traction control system is one of those things that is fussy on the car. Mixed tires/sizes greatly affect the control system more than one would think. I have noticed that different air pressure settings can affect the way the tracton contol system works also. It is one of those things on the Prius that is over engineered imo.

Ron

 

When you correct the tyre pressures test the car again to see if you still have the same problem "I think it will clear" given that the left hand side of the car has the tyres at about 3 psi higher than the right. This will affect the rolling radius of the tyres something the Prius is very fussy about.

If it does not clear the problem try changing the fronts to the rear (correcting the pressures) and try again.

What ever pressures you choose the rears should be about 2psi less than the front. Most people here recommend either 40/38 psi or 38/36 psi.

From what I can tell, "because there are so many Michelin tyres with similar names" the Energy savers with green X are summer tyres. Energy saver + with green X are summer tyres but have better wet braking.

There are 6 different Primacy tyres but I assume you have the Primacy HP again are summer tyres but with good wet braking.

Please let us know how things progress.

John (Britprius)

 

If the Primacy's are worn down compared with the Energy savers this will make matters worse. The winter tyres should improve matters.

The Prius not only has traction control, it has stability control and abs. All work basically by checking the speed of each wheel against the others, and small differences can set it off.

John.