Trouble with Smart Cruise Control?

[tnrrbear]

So, I'm brand new to the Genesis family and brand new to this forum. I came home two weeks ago Saturday with a 2016 Montecito Blue Genesis 3.8 AWD Tech. I absolutely love the car, it's by far the nicest one I've ever owned. However, a week ago Saturday we took a little trip, about 25 miles or so, and it was my first opportunity to use the Smart Cruise Control.

We were on a fairly smooth highway with a speed limit of 55 and traffic was light. I set the cruise at 55 and set the distance for the traffic in front of me at 3 car lengths. At first everything seemed just fine and the car was cruising along smoothly, running about 1,500 RPM at 55 mph. Then we started coming up behind another car. The car downshifted and the RPMs jumped to about 1,900. I thought that was somewhat odd, as I expected the brake to engage or the RPMs to drop in order to slow the car.

So, we're doing about 50 now behind this car going downhill and the car downshifts again, now were up to about 2,300 RPM. I start feeling the car jerking and you can tell the brakes are applying trying to slow the car down while the engine is revving higher and higher. The car is slowing, but I'm getting a little concerned now, so I proceed to tap the brakes to disengage the cruise. But, instead of a smooth disengagement, the car brakes extremely forcefully, jerking us forward in our seats. My husband, in the passenger seat said, "What did you do that for?" I said, I didn't, the car did.

So, I wait a few minutes till traffic clears, then we're back up to speed and I engage the cruise at 55 again. For a minute or so, were at 1500 RPM cruising smoothly. Then we go up an incline and the car downshifts, which seems normal to me. But as we crest the hill and level off the car downshifts again, jumping us up to 2,400 RPM. Now we're going downhill and the car downshifts again, now we're up to 2,800 RPM at 55 mph. There is no traffic in front of us. We get to the bottom of the hill and the car downshifts again, now we're up at 3,300 RPM at 55 mph. I hit the brake again, this time expecting the harsh stop and sure enough, the brakes grab ferociously, jerking us forward.

So, I took the car to the dealer this morning and took a test drive. Their Tech drove the car on the interstate, and in the space of about 2 miles with no cars in front of us, the car downshifted to 4th gear at 65 mph, running about 4,000 RPM, before he turned it off. They tried reinstalling the software which didn't help. So, now they are switching out my entire cruise module with another Genesis they have on the lot. (Evidently this is the fastest way to try to get my car fixed which seems a little weird, because they're cannabilizing another new Genesis).

So, as much as I love all the features and the look and style and driving feel of my new Genesis, I'm not very thrilled to have a brand new car in the shop for an extended time for a major repair less than two weeks after I got it.

 

[balfor]

It does sound like something is wrong, but driving conditions can play a part too. Were you driving on steep grades when this happened? I have noticed the smart cruise as good as it is will have trouble on steep hills just like any other car. The downshifting could simply be the car trying to maintain set speed on a decent. Although rpm may seem high, it isn't as long as the redline is not exceeded which the computer should not allow to happen in any case.

As for the sharp braking, I once had this happen when I did not trust the car to stop when rapidly approaching another car. I manually hit the brake just as the cruise was doing it for me, leading to a faster than anticipated stop. The solution seems to be either trust the system or disengage with the cruise button so braking is disabled then brake normally.

As a side note, I actually now run the smart cruise at a longer distance than I used to, I have found the short distances almost nerve racking as the car is capable of following quite closely. Maybe I just don't trust computers enough! At a longer following distance you have more notice of the car slowing and have time to intervene manually if needed.

 

[greekgeek]

Hope that fixes the problem. So far no issues at all with mine, just the annoyance that the so called Smart cruise control is blind to stopped vehicles in your lane.

 

[Genesisimo]

Thanks for posting. I have my 2016 3.8 RWD Tech back after 3 weeks to diagnose and fix a fuel line and fuel pump issue that cropped up on day 10. It is hard to stay mad at this great car. I'm learning to work with the smart cruise in insane Los Angeles traffic. The delta between the set speed and the speed of the car in front makes a big difference. So does the following distance, any hills or curves, and who knows what else. So you do have to pay attention! In stop-and-go traffic, I set the speed at 20 or 25, following distance 1 or 2, and let the Genny do the driving. In fast-moving traffic I set speed a hair above the speed of traffic and following distance at 3 or 4. It does freak out if someone whips in front of the car. (This happens about every 10 seconds in L.A.) Otherwise it works as well or better than the first-generation system in my 2006 Acura.

 

[tnrrbear]

It does sound like something is wrong, but driving conditions can play a part too. Were you driving on steep grades when this happened? I have noticed the smart cruise as good as it is will have trouble on steep hills just like any other car. The downshifting could simply be the car trying to maintain set speed on a decent. Although rpm may seem high, it isn't as long as the redline is not exceeded which the computer should not allow to happen in any case.

As for the sharp braking, I once had this happen when I did not trust the car to stop when rapidly approaching another car. I manually hit the brake just as the cruise was doing it for me, leading to a faster than anticipated stop. The solution seems to be either trust the system or disengage with the cruise button so braking is disabled then brake normally.

As a side note, I actually now run the smart cruise at a longer distance than I used to, I have found the short distances almost nerve racking as the car is capable of following quite closely. Maybe I just don't trust computers enough! At a longer following distance you have more notice of the car slowing and have time to intervene manually if needed.

Balfor, these were quite gradual, mild grades we were traveling on. The worrisome part was that the car never upshifted back to a higher gear once we were running on level roads. As a matter of fact, the car would continue to downshift and hold those high revs until you turned the cruise off.

I spoke to the manager at the dealer today and they hope to have my cruise module replaced by the end of the day Monday.

 

[tnrrbear]

Thanks for posting. I have my 2016 3.8 RWD Tech back after 3 weeks to diagnose and fix a fuel line and fuel pump issue that cropped up on day 10. It is hard to stay mad at this great car. I'm learning to work with the smart cruise in insane Los Angeles traffic. The delta between the set speed and the speed of the car in front makes a big difference. So does the following distance, any hills or curves, and who knows what else. So you do have to pay attention! In stop-and-go traffic, I set the speed at 20 or 25, following distance 1 or 2, and let the Genny do the driving. In fast-moving traffic I set speed a hair above the speed of traffic and following distance at 3 or 4. It does freak out if someone whips in front of the car. (This happens about every 10 seconds in L.A.) Otherwise it works as well or better than the first-generation system in my 2006 Acura.

Glad to hear they fixed your fuel line/fuel pump issue. I do NOT in the least envy your driving in LA. My husband is from Hermosa Beach and drove in LA traffic for all of his driving life until we moved to Vermont in 2011. We both LOVE the laid back, much less hectic traffic here. It's must easier on the blood pressure!

 

[tnrrbear]

Hope that fixes the problem. So far no issues at all with mine, just the annoyance that the so called Smart cruise control is blind to stopped vehicles in your lane.

That's when these cars need vaporizing lasers installed in the grill.

 

[celltech]

My biggest complaint with the smart cruise is its lack of smoothness and grace when coming to a stop. It really seems to wait till the last second then brakes way harder than I would expect. And then assuming not more than 2 seconds go by after it has stopped, it takes off too slow compared to others around me.

In my opinion it's best suited for open highway driving where you can coast in and out of the lanes and let it just maintain a buffer. Using it in dense traffic is just too nerve racking...

 

[BJCaspianBlack]

My biggest complaint with the smart cruise is its lack of smoothness and grace when coming to a stop. It really seems to wait till the last second then brakes way harder than I would expect. And then assuming not more than 2 seconds go by after it has stopped, it takes off too slow compared to others around me.

In my opinion it's best suited for open highway driving where you can coast in and out of the lanes and let it just maintain a buffer. Using it in dense traffic is just too nerve racking...

I would agree. It waits far to long to start braking and then brakes to hard. A matter of software and the legal folks.
I agree best used on the highway

 

[trespinosranch]

I've only had my Genesis 3.8 AWD Ultimate for a week but did have a chance to check out the cruise control on a two lane road, 55 mph speed limit, with very light traffic. The car slowed as expected when I approached a slower moving pickup truck. After a mile or so the truck moved to the right edge of the road to turn in to a driveway. My car again slowed as expected but when the truck was entirely out of my lane (on the shoulder...but there was no edge line) my car came to a stop, even though the road was wide open. If anyone was behind me I'm sure they would have been upset and/or rear ended me.

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[greekgeek]

That's when these cars need vaporizing lasers installed in the grill.

Amen. What is this, the middle Ages?

 

[tnrrbear]

So, here's an update on my story, and frustratingly, it's getting worse. The service manager called me at 3:30 pm today. I was SOOOO hoping he'd be calling saying my car was ready to pick up. It was more bad news, however.

He said that after replacing my cruise module and some of the radar sensors, they took my car out for a test drive. He had the car hooked to his lap top while they were testing it. He said that now, as long as there is no car in front of my car, that the cruise will downshift and upshift as it should going up and down hills. BUT, if there is a car in front of my car and my car's radar detects it, the car still downshifts, repeatedly and will never upshift and that the laptop connection showed that it also disabled my AEB (Autonomous Emergency Braking System). So, now they think that module that controls my AEB system is faulty and they are replacing it.

So, I have to wait until Wednesday when the part is supposed to come in to find out if this is even going to fix it. If they tell me it's not fixed, I guess I'm going to ask them how I start the process of getting me a replacement car. This is so freakin' frustrating!

 

[Aquineas]

tnrrbear welcome, and I'm sorry to hear about your problems with the cruise control. I am keeping track of your issues with interest because honestly in the Houston area we don't have any hills, and it dawned on me that I've never driven my 2nd gen with the cruise control on a hill or mountain. I'll have to try this out on Thursday when I'm in Austin. Hopefully your issue is a module replacement and all will be okay.

 

[Florida Alan]

I have only had my cruise on one time, and couldn't figure out how to adjust the distance between cars. It looked to be set at 3 or 4 and I didn't know how to change it.
Thank you for your reply.

 

[StarPower]

To adjust the distance, use the button circled in red in the picture below. This is on a 5.0 Ultimate, but I think it's in the same position on all cars. I've found that the closest setting (no bars) maintains about a two second following distance, while the farthest setting (three or four bars, I can't remember which) maintains about a four second following distance.

I have noticed that SCC likes to downshift to use engine braking to reduce speed, but it's never been anywhere near as abrupt as what the OP described. If it's a small adjustment (around 5 MPH or so), it'll downshift. It seems like if it needs to reduce speed by more than about 10 MPH it'll use the brakes.

I've also noticed that, if SCC is braking, the brake pedal is a lot more firm than normal. It'll remain firm if I apply the brakes manually until I release the brake pedal. It does cause some abrupt braking if I have to take control, but I think it's just the way the system operates.

Lastly, someone mentioned it stopping for a car stopped on the side of the road. I've had it apply the brakes for parked cars before. The sensors can't always tell if a car is in your lane, and will usually fail conservative.

Overall, once you get used to it, you'll know when it can be convenient and when you're better off controlling it manually. I've found that it's good for highways with light traffic or two-lane roads with heavy traffic (so no one cuts you off). It doesn't do well on city streets with parked cars, and in heavy traffic I'd rather be fully engaged. It also helps to know what to expect from the system so you know if there's a problem like the OP had.

You can switch to normal cruise control by holding the range button for about three seconds (red-circled in the picture). Just don't forget and expect the car to slow when approaching a slower vehicle.

 

[trespinosranch]

^Great post. Lots of good info. Thanks from a new Genesis owner. I learned a few things.

 

[tnrrbear]

So, latest update. I got the car back yesterday afternoon even though the cruise issue is not fixed yet. I have to bring it back in to the service department next Tuesday morning. They are flying in a tech specialist from Hyundai as well as the regional service manager is coming from Albany to see if they can nail down the issue.

They told me that the new AEB module that they replaced did nothing to fix the problem and they are at a loss for what is causing the problem. They told me NOT to use the cruise as it could cause the AEB system to become disabled. This is NOT the experienced I envisioned when took delivery of this car. I have feeling in my gut that this time next week I'm going to be talking to them about my replacement car.

 

[Florida Alan]

To adjust the distance, use the button circled in red in the picture below.

Thank you.

 

[ahearn]

I had a chance last week to get my 2015 Genesis out on the highway for about 700 miles, using the smart cruise control much of the time. It worked as expected except for one incident when an 18-wheeler suddenly pulled into my lane and the car didn't start slowing, at least not fast enough for me, which caused me to hit the brakes to disengage. Therefore, I believe the OP definitely has a defective system because I didn't experience any of the heavy downshifting she mentioned.

BTW, I also was able to give the Lane Assist system a good workout. I love it, it worked beautifully except for a couple of time when the highway had been temporarily altered around a construction area and the old lane lines had not been totally erased. The car recognized them even though they were barely visible.

 

[tnrrbear]

So, They've had my car for the 2nd time since yesterday morning. The special tech they flew in from Hyundai spent half the day yesterday with one of the service dept. mechanics driving the car trying to diagnose the issue. They were able to duplicate the downshifting problem over and over again, but they were never able to get any diagnostics to indicate from where the problem is coming.

So, they called me this morning to tell me that Hyundai has approved for them to replace my entire master cruise computer. They had already replaced my radar cruise module and the AEB module. But they tell me this is the main control module that controls all functions of the cruise control. It is supposed to be replaced tomorrow.

If they replace this module and the problem isn't fixed, I'm going to ask for a replacement car. Out of the first three weeks of ownership my car has been in the shop for 8 days now. This has NOT been the experience I hoped to have with this car.