bdeweese

Greetings! I own an 03 SL500 and have had distronic issues since purchasing the car a few years ago.

I recently used xentry to diagnose the system and it identified an internal error in the DTR (N63/1) control module. Replaced it with a used (latest version) unit today. Reran xentry and the fault is now gone (and no other faults reported).

However, upon road testing the car it still behaves the same as pre-replacement of the module. I’m glad I replaced the faulty unit - but still would like to actually fix the errant behavior.

So here’s what’s going on. The Distronic function actually seems to work fine if I’m within Distronic’s “range” for a car in front. As long as I’m in a steady line of traffic - regardless of speed - it pretty much sticks like glue. Slows/speeds up to keep pace with the car in front, etc. However, as soon as the gap in front exceeds that “range”, it disengages. If I try to reengage without being “in Distronic range” of the car in front - i.e. go into normal “cruise control” mode - it quickly disengages with the “distronic - external fault. Reactivate” message on panel.

Xentry/manual suggests that this may be caused by interference. Not sure what it might be since it happens everywhere we travel. Would have to be something from within the car. Also - if it’s interference, why would it only happen when I’m out of range of cars in front?

The other thought I have is regarding the front sensor alignment. Since distronic seems to work when it detects a car ahead - is it possible a misaligned sensor would cause this behavior? I thought when there was no longer a car detected in front that the unit just reverts to “standard” cruise control and just tries to stay at whatever speed I’ve set?

I did also inspect and clean the front sensor today - as an added measure. It didn’t look bad - but no idea when that was last done. Any thoughts/suggestions? I’m stumped.Thanks!!

bdeweese

UPDATE. Decided to replace the front sensor/radar unit with a replacement from eBay. Worked great for about 45 miles - mostly in traffic - but even through some stretches with no traffic ahead. But then around 45 miles or so I got the usual external malfunction -reactivate message. It did thus a few more times and then worked well for several more miles before failing again.

To recap - I have now replaced both the DTR control unit and the radar head unit. Still have the issue of Distronic failing with “external malfunction - reactivate” - but only when there are no cars detected in front of me. That seems odd - and it seems like that could be a clue to the underlying issue. The system performs flawlessly as long as a car is detected ahead.

Anyone??

Thrasher5621

I have the same issue on my 2003 SL55 AMG. Did you ever figure anything out. I have done everything you have. Sometimes it works... other times it kicks out one after the other. Any thoughts welcome!!

JettaRed

iTrader: (1)

I don't have this exact problem on my 2015 SL400, but I do have regular fault codes for the radar sensors on in the bumper (far right and left sensors) that there is external interference. However, Parktronic seems to have work normally and so does Distronic. The only problem I seem to have is the auto parking feature rarely works (though I have only tested it and never actually used it).

In my case, I usually ignore the problem, but I can see how it is more annoying with Distronic.

yovenim

On a long drive yesterday the sytem repeatedly switched itself off with the message 'Distronic External Malfunction'. Does that mean that another system that feeds data to Distronic has a problem? Everything else seems okay and there are no other warnings. Thanks

JettaRed

iTrader: (1)

Where there any DTCs associated with Distronic? Have you recalibrated the Distronic unit (A89)? Calibration MUST be initiated with XENTRY and driven for 10-15 minutes in a fairly straight route with some vehicles, but not stop and go traffic. If you don't have XENTRY, I know calibration can be initiated using Launch Creader Elite BENZ. The actions are taken within the A89 module. My car is a R231, but you should be able to do the same using DAS since you have an R230. Generally, you need to get to the Adaptations screen for A89. Then go to Initial Startup with adjustment drive and without replacing the control unit. Since you have replaced the control unit, you may need to do the adjustment drive with replacement of the A89. Just driving around without initiating calibration won't work, which is what sounds like has been happening.

First check the Adjustment Values Actual Values to see if you need calibration or if your values are outside the specified values.

Then proceed with calibration.

bdeweese

Late response - but this is very helpful. I never did get this resolved, but had the car up on blocks most of the winter working on a bunch of other things.

One task was to replace all 4 struts. Once completed, I took it to the dealer to have an alignment of the suspension and the radar/distronic. The dealer contacted me yesterday and requested that the mechanic be allowed to drive it home and back - as they need to get 100km on it (presumably, the calibration drive you reference?) Today, they indicated that they were still getting some errors, and so the tech would need to log some more miles on it this evening (hadn’t yet reached the 100km).

Curious if this sounds right? The tech indicates there are no other errors reported in Star and that the car and radar unit are now perfectly aligned. Really hoping they get this sorted out. Thx!!