Why Did My Forward Collision Alert Automatically Turn Off?

This morning on my way to work, the orange light on my dash was on saying the forward collision alert system was turned off. I looked through my settings and it was on in the menus, and I pressed the button on the steering wheel with no change. It was snowing some, but nothing too crazy. I could still see over a mile. I have read that bad weather such as heavy rain or snow can cause the system to not function, but I am not sure that this is what I experienced. If that was enough to make it turn off, I am disappointed.

 

Sensor dirty or covered with snow?

 

In inclimate weather such as snow it will shut itself off to prevent potential braking on slick road when its not needed

 

The sensor is clean and the snow was not enough to cover anything since it was 35 degrees and the truck was warm, and in a garage when I started. Does it brake automatically when it senses an impending collision even without the cruise control set? I was under the assumption that it only alerted you in that situation. If that is the case I can understand why it would need to turn off the braking part, but wouldnt it still be useful for the alert to still work, without the braking?

 

It will alert you, and if you do not take action in a timely manner it will assist in braking to lessen the impact in the event you never take over. But the second you apply input (brake, steer) it will let you control everything

 

This morning while driving to work, no snow, no rain, the light just appeared and showed it was off for the pre collision system. After a few seconds it went out and about 10 mins later came back on again then off again. Can cold weather cause this or is this simply a malfunction for the dealer?

 

Mine has turned off and back on again by itself a couple times. I cleaned the glass on the upper portion of my windshield and the Toyota emblem on my grill to be safe but it seems to return to normal on its own after 10 minutes or a couple miles. I’ll mention it to my SA next time I’m in. This and occasional false alarms seem like first year teething issues for TSS on the tacoma.

 

Mine turned off today for the first time. 1st snow of the season did it.

 

I have a couple false alarms but compared to a couple other forward collision alert systems I've dealt with it's not a concern of mine. For example, my 2011 Jeep Grand Cherokee would alert me while driving in the city almost every time theres a curve with a barrier wall close to the road. I could not pass tractor trailers with the adaptive cruise on. The tacoma does have problems sometimes with tractor trailers, but it's understandable IMO.

My tacoma is the 4wd SR5. I have noticed too that the forward collision alert turns off when traction control is off and when traction control is active (as in wheel slippage). I dont know if it works any differently with manuals or models with different features.

 

It will also turn off if it is snowing or raining hard enough even though the sensor is clean. Computer must have some sort of algorithm to determine if it has a clear view or not. I have had it happen a few times in bad weather in Colorado.

 

The only irony here is heavy snow or rain might truly be the time you NEED this function to work. Especially in the dark.

 

I've had mine turn off when parked outside facing the sun, I'm not sure if hot temps would hamper it. The only other time was after offroading and it was heavily splashed with mud etc.

 

Considering how many people are switching to pro grilles and doing makeshift things to get the sensor to fit, it would be nice when people complain about it, if they also said "I got a little bit of jb weld on the sensor when installing the pro grille, but not too much".

It's been basically 3 years on my wife's rav4 with tss and one year on my Tacoma in a snowy region. I have had no malfunctions yet.

 

...and this is the reason self driving vehicles are challenging. Toyota is not alone with this problem. Every vehicle does this in inclement weather.
The news is they are going away from radar and going towards FLIR. This is going to be big, eventually, in five years or so. Until then, just understand that, if the sensor shuts off, it's for a good reason. You don't want to think something is working when it cannot.

 

In my case I have not switched out any parts. Its still bone stock, for now. I was rear ended last week so that bumper will be changing soon.

Thats good to point out. Every couple months you see an article about a Tesla killing the passenger because they hit a firetruck on the side of the road while the car is in the assisted driving mode. Tesla always has to point out that the cars are not self driving, and they intentionally ignore those types of situations. Its also why the sensors dont work at low speeds. The technology is much more advanced to be able to sense those situations and realize that the sensor isnt just picking up a stop sign or a parked car on the side of the road. The sensors on these trucks are not sophisticated enough to tell when the radar is coming back from snow or rain, and when its a car.

 

Mine turned off in the rain a couple of times but that's because I installed the TRD Pro grill but not the ugly garnish to cover the sensor. When I had the stock grill I had no issues in the rain.

 

Mine did this to me today randomly...also reset my average mpg. Sunny day too so I can’t see weather being an issue

 

Mine does it all the time! But I do have an aftermarket Pro grill on.