DavidNJ

I was driving along and game to a light. As I slowed down the 4 red lights on each of the front and rear Parktronic displays came on and the buzzer went on continously. This continued several more times on that trip. And again after I stopped.

The dealer said the computer showed a 'sensor' fault and reset it. I said that isn't adequate. It is obviously a fault in the control unit since in normal operation the system can never display only the red lights (the yellow warning lights would also be shown).

However, the dealer didn't know what the problem is. Did anyone here have a similar problem? If so, what was it?

Thanks,

David

MBenzNL

Sensor failures are common problems...it only takes one stone, pebble, rock - or whatever else flies up from the road due to traffic in front of you - to hit one of the front sensors to create a failling sensor...one there is a failure in the PTS system it will light up the displays and will make noise.

greetingz,

DavidNJ

Yes, a sensor failure could respond like a triggered sensor. However, then all the yellow lights would be set in addition to the red lights. And with a 60% chance of being in only one quadrant, and 100% chance of being on one end of the car.

Even if it was a wiring failure, the control unit would have to respond as if it was a sensor signal. And the response to a failed sensor would be an error mode: dash warning message, system shutdown. That is what MB does for even the airbags (another first hand experience that the dealer says was traced to a short on the seat frame.)

David

etenn

Had a similar problem. Dealer replaced sensors (they have to be painted to match) and no more problem.

MB Fanatic

Yup I was going to San Francisco when it happened. I think there were some rocks that hit the sensor, luckily they didnt cip the paint anywhere else on the car. Dealer replaced the sensors once I got back and painted the thing.

alewifebp

I've had the same thing happen, especially while driving in NYC. I remember one time hitting some rough pavement that spewed up some dust, and it did that. After I started driving again, operation returned to normal.

Marcus Frost

Currently have the same problem, will be having the dealer fix it when I go in for my SBC recall - along with a few other fixes that need to be done.

Still love the car!

-m

konigstiger

P-B-54.65/104a - JAN04 Parktronic Triggers without Obvious Cause. The front PTS sensors may be reacting too sensitively. New front sensors are available which are less sensitive and should be installed. However, it goes on to note that if a fault code is stored in the PTS control unit (e.g. sensor faulty), it is not necessary to install a less sensitive sensor.

The TSB dates back to JAN04 and therefore, in theory, your 05 should already have the less sensitive sensors. I would ask the dealer to confirm this. Time and time again here on the forum I have read that vehicles coming off the assembly line well after the TSB effective date did not have the appropriate update. If, in fact, it is found that you do not have the new sensors I would request that they be installed regardless. On the other hand, if you do have the less sensitive sensors your dealer simply did what MBUSA instructed them to do, reset the system.

FYI, there is another TSB P-B-42.20/35 – MAR04 Parktronic System Intermittently Nonfunctional. Here it instructs the tech to check the switch at the foot operated parking brake for ease of movement. If the switch exhibits resistance during its range of travel, it will need to be replaced.

Best of luck.

Baby Jocko

No, I have not had this problem. But, I agree that it, of course, cannot be a sensor problem (or foreign objects blinding a sensor) and would not be satisfied with a reset for a fix.

mqtutve

I have this problem. The Partronic goes red (the red middle indicators) both in front and rear without any reason. The failiure comes and goes from time to time. I have cleanded all sensors and disconnected the battery. I think there is some command unit problem hence it happens both in the front and in the back regkes if I have the reverse in.
The only thing I think I can say is that if the battey is low the problem appears more often

DavidNJ

It is different than the problem we had. Ours eventually went away on its own if I recall. Did the dealer look at it?

mqtutve

I see. I)t just starts beeping without any reason. No I have not spoken with the dealer yet because the will charge just for checking so I started here

MPOW33R

My issue is different. It just started today.

So when I come to a stop on the dash Parktronic led guide
(2) leds on each side lit up

then when I threw it in reverse to get in my drivway
the Driver Side rear lit all the way thru RED n Yellow as If i were about to hit.

Did this same thing several times in the past hour.

Any clues on the Front AND rear acting up?

NorsemanE320

Have had this problem many times, always due to broken sensors. The combination of crack in the painting and wet climate is not good for this sensors. I have always changed my rear sensors my self, but now i have one or two faulty sensors in the front. Anyone who have a good DIY for replacing front sensors??

konigstiger

NorsemanE320

Hi and thanks again Konigstiger! Do i understand it correctly that the sensors will come out just by (gently) remove the front bumper list? The workshop charge $300 each, å heavy overprice if it's that simple...

luffy09876

I apologize for bringing up this old thread. I had a similar issue with my vehicle recently; the Mercedes Parking Assist is not working properly, as I thoroughly checked the issue, I found out that I had a bad grounding issue in the system, I perfectly tight the grounding points to fix the issue. I came across an in-depth article that may be worth reading. Search for "Troubleshooting Mercedes Parking Sensor Parktronic Problems on YOUCANIC" and you will see an article that goes over common causes and possible fixes. You can read about it yourself. I hope this information can assist someone else with a similar issue.