Recently I have done inspection on some of the Mercedes Benz that are equipped with Distronic Plus for driving that were having concerns and I want to clear up how these system work and when you know there is a problem with it. These systems work off of radar position in front of the car behind the grill area and has a Radar Sensor and an Adaptive Cruise Module, it also uses the brake system. This Distronics Plus can be turned on at 30 mph or above and the distance can be as close as 100 feet up to a few hundred fee this is the best distance to use.
Distronic Plus On works like the Cruise Control;
Let me start with Distronic Plus and how it works and what the warning sign mean. Distronic Plus is a system designed to keep automatic speed regulation with control proximity of the vehicle in front of you traveling at a slower speed.
How it works is when you are driving behind someone driving slower than you are when the Distronics Plus is on, let me say 60mph and you set the Distronic at the speed of 65 and the distance at 100 feet, this means if you are driving 65mph and you come up behind another car and there speed is less than your speed the Distronic Plus slows the car down in turn helping you avoid a collision.
Some people may think, this is Collision Prevention and may complain “My Collision Prevention Assist is not working right” but they may mean my Distronic Plus is not working right meaning the car did not slow down when it approached the slower vehicle in front of them and the brakes did not apply and slow the car down as designed to do.
Now if you turn on the Distronic Plus and then see a warning that says Suspended that means the brake system was suspended (meaning a problem is present with the Distronic Plus) keeping it from working properly when you get to close to the slower car in front of you, the warning sound will start to beep loudly warning you to slow down, this does not mean the Distronic is turned off.
The Distronic Plus will not turn off until you press the brakes and then you will see the warning “Distronic Plus Off” meaning you hit the brakes and now the Distronics Plus is off.
You have a Problem when you see Suspended after you turn on the Distronic Plus but did not hit the brakes and if the car speed up when it should not and if you get a warning when you think everything is working properly
Active Lane Keeping Assist;
This Active Lane Keeping Assist is designed to keep the car in the lane you are traveling at. The way this Active Lane Keeping Assist works when you are driving in a lane and then the car veers out of your lane and starts to cross the lane left or right of you the brake system will activate and cause the car to pull back into your lane, this may save you from getting hit or hitting another car, this may also be confused with Collision Prevention Assist.
When the brakes apply during Active Lane Keeping Assist they will slightly apply but not enough to cause the car to jerk or move abruptly causing you to be afraid, the brakes will apply in the right front and right rear if you are drifting to the lane to the left of you and if you are veering to the lane to the right of you the left front brake and the left rear brake will slightly apply to cause the car to come back to the center of your lane avoiding a possible collision from you hitting another car or from you getting hit by another car.
You can test this by turning on the Active Lane keeping Assist by drifting into another lane left or right and see if it pulls the car back to the lane as designed and if not then you have a problem.
Active Steering Assist;
Active steering assist is designed to help you the drive keep the car centered in the lane stopping you from drifting to close to the left or right lanes. This is for you if you are drifting left and right the way some drive do when driving, you may have seen other driver drift left and right when if front of you making them appear to be drunk the way a drink drive will do.
You can test this Active Steering Assist by making the car drift left or right while in the center of the lane, it should pull the car back to center and if not then there is a problem.
Collision Prevention Assist;
Collision Prevention Assist is designed to keep you from getting hit by another car when driving, it works off Radar to watch your soundings area of your car. If a possible collision appears that may happen it will apply the level of breaking you need in hope to help you avoid getting hit or hitting someone else avoiding the collision. Your Technician can test this by using the shop XENTRY tool or it may be called the Star Diagnostic tool for testing and reset, it taking approximately 1 hour to do the job.
If you have problems with your vehicle you can get help and you can win but you must have records of repairs on the concerns you have and have attempted to get those repairs made more than three times unless it is a safety issue which is two times, meaning Brakes or (SRS) Safety Restraint System. There are a lot of good attorney who can win for you but you must contact one of them. Thank you and pass the word forward if you need help or know someone who does. I am a certified Craftsman and certified by ASE, Detroit Diesel, Hybrid trained and a Certified Appraiser with over 40 years of hands on experience. I have also been on the witness stand over 58 times with over 800 deposition and have never been impeached.
PLEASE LEAVE ALL TESTING TO THE EXPERTS JUST TELL THEM WHAT YOUR CAR IS DOING AND THEY WILL KNOW WHAT TO DO, MOST OF THE TIMES.
Jackie Winters
Lemon Protection
800-700-0109 with any question.