Presafe/dISTRONIC/lane assist/blind spot assist failure
Error messages on dash:
1. Blind spot assist
2. Lane assis
t3. Pre safe brake check manual
4. Distronic plus, only when I enable it
5. Auto high beams don't have an error but I think they don't work well and might be related if they share a sensor or alignment
Troubleshooting so far:
1. Replaced a fuse for dISTRONIC, didn't do anything
2. Oil change, car needed it anyways
3. Reset service a
4. Cleared codes with scanner and 530900 and 530700
At random, very rarely all systems work, leads me to believe the sensor is corroded or misaligned.
Visual inspection shows a dent repair near the b29/3 area in bumper, minor dings and such on bumper Paper towel wedged in two bolts maybe keeping something straight?
Codes from scanner:
531300: Check component 'B29/3(Right front bumper DISTRONIC(DTR) sensor)
530400: Component 'B29/3(Right front bumper DISTRONIC(DTR) sensor) is disrupted by interference from an external transmitter
520400: Component 'B29/2(Left front bumper DISTRONIC (DTR) sensor) is disrupted by interference from an external transmitter
CURRENT 530700: check component 'B29/3(Right front bumper dISTRONIC(DTR) sensor)
CURRENT 530900: check component 'B29/3(Right front bumper dISTRONIC(DTR) sensor)'
Other questions,
1. Are there fog lights for this car?
2. Grille replacement, black e63 style or diamond?
2a.I Prefer black luxury style with dISTRONIC and hood ornament
does anyone have a link to one they recommend or a good store that could help?
3. Front lip is beat up, replace in black, how tricky?
Last edited by Boarderjosh10; Oct 13, 2023 at 08:33 PM.




The following 2x codes I crossed out don't prevent Distro+ from working. I know that for fact.
531300: Check component 'B29/3(Right front bumper DISTRONIC(DTR) sensor)
CURRENT 530700: check component 'B29/3(Right front bumper dISTRONIC(DTR) sensor)
CURRENT 530900: check component 'B29/3(Right front bumper dISTRONIC(DTR) sensor)'
Sounds like your Right side front radar Module is history - Either smashed in a parking lot or soaked with rain through its non-waterproof connector.
It is said that Rear Radars are plug-n-play but front ones need Xentry calibration.
🤞
Last edited by CaliBenzDriver; Oct 13, 2023 at 10:18 PM.
Thank you




These units are wasted and non-repairable once penetrated with water.... the harmess connector may be badly oxidized as well if water came through its pins.
I have not delt with these radars modules at the front, only rear locations - WIS calls for a bumper off procedure but there may be a chance to access radars by removing the front belly-cover. 🤞
While in there RTV every waterproof connector you come across... including headlights $$$$ - Disconnect batteries to prevent creating bogus faults during surgery.
It could be a rat chewed on the harness and your modules are A-ok!





I've got a 2015 E250 and I'm having the same issues but only intermittent.
All the assists seem to just randomly become inoperable. come on and off.
Same with the Distronic Plus but at different times.
I'm assuming that it's a case of getting the faults scanned and then replacing sensors or is there a common fuse/wiring harness that may be faulty?
The short list involves low voltages glitches (batt, alt, gnd,...).
It's not weekend afternoon walk in the park to melt this snow ball.
Some of these modules are subject to water egress - Troubleshooting's necessary to recognize offenders.
Any idea on checking what needs to be done in order to resolve this. Check wiring, replace sensors or check for corrosion?
These sensors costs a lot and i thing only require reset in order to start working, no programming requires.
Appreciate any help with this please.





