The Sting

Hello all,

For my (pre-facelift) W221 S350, I sometimes get this error message whilst driving at relatively low speeds (let's say between 10km/h and 60km/h) with the usual beep and message flash :

Distronic plus inoperative, consult owner's manual
Parktronic inoperative, consult owner's manual

Any idea what's causing this?

(By the way, both Distronic and Parktronic operate just fine)

listerone

Bad sensor(s)?

Jan AMG

Try the small battery of the radar.. Otherwise re-calibration might help.

marthyh

I have read it could be the auxiliairy battery in the rear is partially depleted,because of driving too little distance with too many electrical consumers on.

Not sure, had it twice and I suspect its interference from other cars..

Diesel Benz

I've seen this error message a couple of times. When I read fault codes with Star Diagnosis, it shows events of interference causing the system to switch off. I guess it could be RF interference on the bumper radar frequency or just reflections of the radar pulses that appear confusing for the control unit at times.

SUNILP

ON pre-face lift 221 cars, the parktronic and distronic close promiximity sensors are located inside the bumper. Shadow memory using DAS will show any interference errors which you can use to pinpoint a problem. I would lead more to a faulty sensor. Event memory will show any connection issues with the sensors. Either way, you will need access to a STAR system to diagnose properly.

SUNILP

There is no recalibration procedure for the close proximity sensors used for PTS and close proxmity distronic. Long range distronic sensor (center of grill) is the only sensor that requires calibration which is not used for parktronic at all.

s600ed

on my 07 I would say once every other week while at a stop light would hear the long beep with the error message but would go away within 2 seconds. first few times brought it to the dealers attention but with no answer, but so far still works ok

The Sting

Same here, but suprising no one has found a solution for it.

listerone

I've gotten the same warning once since buying my Bluetec but it was during a really sloppy snowstorm that featured lots of slush on the road.I assume that one of more of the system's sensors were obscured by the slop,thus causing the warning.Never got the warning again.

Diesel Benz

First of all, glad to see one of the real experts on-board since awhile (I figured a one year gap between posts).

In my case I did not see any connection issues in the event memory. I did not even try to figure out interference issues from the shadow memory. I've got the star kit (actually two, PartD and SDconnect) but most likely I would need instructions for this.

For early W221 cars there is a software update too for the bumper radar units. Mine have not been updated, according to one technical bulletin this could reduce the number of events when Parktronic Plus gets disabled?

listerone has a fresh car and even a bit different Distronic Plus implementation (if I remember right, it would come with ultrasound based sensors plus two short range radars plus the main radar while older cars have no ultrasound sensors but four short range radars behind the bumper). The radars tolerate surprisingly much snow but I have also seen once or twice the system switching off from a lot of slush covering the grill and the front bumper. This is quite reasonable unlike perhaps the other scenario where the system switches off.

Max Gothenburg

I get this long beep with error message every now and then. Maybe once a week. Everything still works perfectly. Did anyone find out what might cause this?

DonnieSnyder

Ok guys I figured it out. I noticed this happening with my pre-lift S65, more recently then ever. Its always at low speeds when your parktronic activates, generally at a red light, stop and go traffic etc. Start looking at the other cars around you, nine times out of ten there's a newer generation ford product lingering in the general vicinity. Its normally a higher end fusion, Taurus, Edge, Escape or their chrome plated Lincoln variants. I'm not sure what type of radar ford used to knockoff the Lexus LS460's self parking system (7 years later), or the BMW 7 series "kick under the rear bumper to open the trunk" feature but it always throws the error codes on my car and its so annoying. I'm wondering if Mercedes has a software update to cancel out the errors. What's bizarre is the Lexus LS never sends out any problems and I'm behind my mothers 7 series all the time and never have any issues with either of them. Has anyone had luck or heard of a software update on this matter?

Diesel Benz

There is a technical bulletin about the SW update that fixes certain Distronic short range radar issues. Depends on your build date if this fix could apply to your car.

DonnieSnyder

Thank you so much I will definitely ask next time I'm in for service. Thank you for the information.

Nickthegreek

I notice it happens to me when I stop in back of a car with backup sensors. I wonder if it is RF interference from other cars

hayden and flo

Jan AMG

You have 2 or 3 batteries depending on the MY.

https://www.benzworld.org/forums/w22...s-550-a-2.html

sdewey

Hi guys! Reviving an old thread because I'm having the same problem with my new-to-me low mileage 2007 S600.

About once or twice a week I'll be in stop-and-go traffic or at a traffic light and get the long beep with the "Park Assist currently unvavailable. See Oper. Manual" warning on the dash for about two seconds. Sounds like I'm not alone.

There are two dealers in my area. Took it to the first dealer and they said it was an interference issue and that I would need to live with it or replace all of the sensors at a cost of over $3k. Took it to the other dealer and they said two of the sensors were faulty and needed to be replaced at a cost of $1500. I agreed to let them replace the two sensors at a cost of ~$1500 as they assured me that would resolve the problem. Ouch! And that didn't even fix it. Told them I'd bring the car back but would appreciate some advice from the community. Seems like there might be a software fix for the early cars? Does anyone have a TSB number that I can reference to help the dealer get it right? Should I replace any of my batteries? From what I can gather I only have two batteries - the starter battery and the big one in the back. In the absence of other errors I'm inclined to think that the battery is ok.

Or is this something that we just have to live with on the early cars?

Thanks in advance!

tx170754

I have the same thing from time to time depending on the cars close to me, it is an interference, you have to live with it, no big deal 😊

DaleB

Correct - there's no fixing it, and I think the dealer screwed you since they should have known that perfectly well. It's a well known issue that every '07 owner deals with. I just try to remember to push the park assist disable button on the dash when I start up. That disables Parktronic when you're driving in town, but leaves Distronic enabled. The other option is to turn the radar off using the steering wheel buttons, but that disables Distronic as well.

BOTUS

clearly don't take your car here they have NO idea about anything - its probably the prevalence of radar detectors that throw so many issues in USA. as of mid 2007 the parking sensors are visible and less prone to silliness

DaleB

It's not radar detectors. They're actually quite rare in this part of the country; very few people bother with them as the highway speed limits are much more reasonable. They were almost universally used back when there was a national 55 MPH speed limit. Now that most states around here are 75-80 on the highway, it's enough for most people. In town the cops are using mostly laser, so the detector just gives you a few seconds advance notice that you're about to get a speeding ticket. I don't think I personally know anyone who actually owns a radar detector. They're just not that useful. Hell, even I don't own one.

The issue is blind-spot and adaptive cruise and parking radars in many of the newer vehicles. My Parktronic alarm goes off at traffic lights quite often. There's always a late model Ford, Subaru, or a couple models of Nissan close by. Occasionally something else, but a Ford Edge is pretty much guaranteed to cause problems. Only at stops, because Parktronic automatically goes active under a few MPH as you slow to a stop.

sdewey

Thanks for the feedback everyone! Not the answer I was hoping for, but glad to hear that I'm not alone. I'm a bit surprised - I can't imagine that there weren't a few original owners encountering this problem while still under warranty by 2010. If I had paid the original MSRP in 2007 and the dealer told me to live with it I would not be pleased.

Someone earlier in the thread mentioned that there was a technical service bulletin for updating the software? Has anyone had this done? Anybody here have a copy of the TSB or the reference number?

BOTUS

I had all my disctronic plus radars and parking radars / sensors updated and the BAS plus, in the last year. it will give you lots more beeps on the BAS plus.... and no change at all on the problems with JLR (and I guess ford as was the same company at one time) and Nissan or temporary traffic light sensors …. (maybe USA use radar on all your traffic lights... we bury metal detectors in the ground...)
But it will make disctronic throttle and brakes different, but not in any positive way...