[JABCAT]

About 3 hours into my 3.5 hour drive today I was coming up on interstate traffic with the ACC activated when my car started accelerating instead of braking. The ACC was set at 78 mph and the car accelerated to 84 mph before I slammed on the brakes. The ACC had worked normally the entire drive up to that point. Once traffic opened up I hit the resume button on the steering wheel and a warning message popped up in the cluster & on the screen that said "you can continue driving. Check sensors or clean them" It also had a picture of the front of the car with a red square covering the area of the sensor.

Has anyone had this message pop up before? It did rain yesterday & this morning so the car is dirty, but that's the first time I've seen that message in 20k mi. I would also think if the sensor was dirty/obstructed it should have popped up a warning at some point when I was driving? The acceleration above the set speed limit is also concerning.

[BroDoze]

So was the radar sensor dirty?

[JABCAT]

Originally Posted by BroDoze

So was the radar sensor dirty?

Based on the image showing the sensor blocked I thought maybe a piece of road debris, like a plastic bag, had gotten sucked up into the grill opening maybe covering the sensor. There was nothing blocking the sensor & it wasn't excessively dirty.

Even if it were, that wouldn't explain the vehicle accelerating well over the set mph.

[RockCrusher]

Some trash -- leaf or something -- could have gotten on the sensor and remained long enough to trigger the sensor blocked warning. Then just as suddenly as it ended up on the sensor it was removed.

The acceleration is a bit of a puzzle. Giving the benefit of the doubt to the electronics (rather than you... sorry) I'm wondering if perhaps you inadvertently hit the increment button?

To be sure from now on you need to be on high(er) alert for this anomalous behavior. If it happens again to me that would justify having the car in to the dealer service department for this.

[JABCAT]

Originally Posted by RockCrusher

Some trash -- leaf or something -- could have gotten on the sensor and remained long enough to trigger the sensor blocked warning. Then just as suddenly as it ended up on the sensor it was removed.

The acceleration is a bit of a puzzle. Giving the benefit of the doubt to the electronics (rather than you... sorry) I'm wondering if perhaps you inadvertently hit the increment button?

To be sure from now on you need to be on high(er) alert for this anomalous behavior. If it happens again to me that would justify having the car in to the dealer service department for this.

I thought that as well (leaf, trash, etc.), but I tried it multiple times after that incident & the same message popped up each time. Re: accidentally hitting the button, I didn't. My hand wasn't near that part of the steering wheel at the time. The set speed still displayed 78 mph on the HUD, even after I hit the brakes. If I would've hit the button, the set speed displayed would've increased.

This has happened at least 3x that I recall where the car failed to initiate braking when approaching traffic; however, this is the first time I noticed the car actually accelerate. It's going in for an oil change next week & I'll mention it along with the persistent "emergency call system inoperable" message. I'm confident it will be one of those "cannot duplicate customer concern" situations.

[TallGibbs]

Originally Posted by JABCAT

I thought that as well (leaf, trash, etc.), but I tried it multiple times after that incident & the same message popped up each time. Re: accidentally hitting the button, I didn't. My hand wasn't near that part of the steering wheel at the time. The set speed still displayed 78 mph on the HUD, even after I hit the brakes. If I would've hit the button, the set speed displayed would've increased.

This has happened at least 3x that I recall where the car failed to initiate braking when approaching traffic; however, this is the first time I noticed the car actually accelerate. It's going in for an oil change next week & I'll mention it along with the persistent "emergency call system inoperable" message. I'm confident it will be one of those "cannot duplicate customer concern" situations.

I wonder if there is a way to request the dealership pull telemetry data to verify the condition (setpoint of 78 mph, actual speed above that, accelerator position, radar sensor distance output, etc)?

[jmg]

You have been having ACC issues for awhile. I've been using ACC to test out the system since I got the car. Now at 1200 miles I haven't noticed any anomalies.

Personally, I think it's your grill protector. I would take it out and give it a try. There are kits you can cut out the grill to not cover the ACC sensor.

[JABCAT]

Originally Posted by jmg

You have been having ACC issues for awhile. I've been using ACC to test out the system since I got the car. Now at 1200 miles I haven't noticed any anomalies.

Personally, I think it's your grill protector. I would take it out and give it a try. There are kits you can cut out the grill to not cover the ACC sensor.

I've had the same issue with & without the protective grille installed (one without & 2 with). That definitely doesn't rule out the protective screen, however.

Of the kits I've seen that go around or behind the ACC sensor, they all have larger openings than the ZunSport. Even with the ZunSport installed, my radiator is still taking a beating from small pebbles.