ace8726872 Report post Posted March 17, 2013 Yesterday I was driving on 101 North past Thousand Oaks, CA to go shopping at near by outlet in Camarillo. I was driving down a long and steep grade and decided I wanted to trn on the Hill Decent Control to see what it did. Before I reached the bottom, my battery was maxed out when I heard this grinding noise coming from the rear of the car. I switched out of the Hill Decent Control and applied gas to stop the car from charging and the noise went away. By the way, this is the video of the freeway section I am referring to. http://m.youtube.com/#/watch?v=8iqnXFNsBd0&desktop_uri=%2Fwatch%3Fv%3D8iqnXFNsBd0 Did anyone observed this before? My first thought was that the car didn't want to charge the battery beyond its capacity and didn't know what to do because it had the Hill Decent Control engaged. What do the other members think about this? Thanks. Quote Share this post Link to post Share on other sites
B25Nut Report post Posted March 17, 2013 I have gone down this same grade several times, the last two with the Grade Assist engaged. I'm always amazed that there isn't any detectable change in sound or the feel of the car. It just keeps me between 65-70 mph. It's frustrating whenthe battery reaches its maximum charge before getting to the bottom of a decent, but I haven't heard any sound yet that's related to it. Quote Share this post Link to post Share on other sites
ace8726872 Report post Posted March 17, 2013 Ok, I didn't think the noise was normal and hopefully it didn't damage anything. There were no issues at all since the noise so I am crossing my fingers. Thanks for the feedback B25Nut! Quote Share this post Link to post Share on other sites
ace8726872 Report post Posted March 17, 2013 By the way, on the same trip, there was a huge accident right behind me where 23 north merges onto 101 north. I was stopped behind a traffic on the right lane of 101 onramp and heard the tires. Loos like some people were distracted and didn't see that the stopped cars, slammed the brakes, causing several rear-end collisions and causing a white Dodge truck to almost flip over. 3 series BMW that was right behind me got rear-ended! It was fascinating and scary to watch this all in my rear view mirror! Quote Share this post Link to post Share on other sites
GrayStrider Report post Posted March 26, 2013 We've only used the Hill Descent Control a few times, and it does change the sound of the car, but I don't think it's like what ace described in the post above. My husband was driving (coming down from Lake Arrowhead on Highway 18 into San Bernardino, CA), so I don't know if he reached the point with the battery showing a full charge or not. Didn't notice anything other than the typical noise it makes when it's engaged. Quote Share this post Link to post Share on other sites
ace8726872 Report post Posted March 26, 2013 We've only used the Hill Descent Control a few times, and it does change the sound of the car, but I don't think it's like what ace described in the post above. My husband was driving (coming down from Lake Arrowhead on Highway 18 into San Bernardino, CA), so I don't know if he reached the point with the battery showing a full charge or not. Didn't notice anything other than the typical noise it makes when it's engaged. It definitely didn't sound normal. I have not engaged the hill decent control since (too chicken to do it). The car up is running perfectly so I am just going to leave it at that! Quote Share this post Link to post Share on other sites
hybridbear Report post Posted April 1, 2013 When we were in this part of Cali on vacation we used the Grade Assist and didn't have any weird sounds other than the noisy engine braking once the HVB is full. There is a whining noise from the regen though that can also be heard when stopping using regen. It isn't that noise that you're hearing ace? Quote Share this post Link to post Share on other sites
