S211 Rear Park Sensors not working - is Tow bar electrics the problem?

Page may contain affiliate links. Please see terms for details.

Mintyfresh77

Member
Joined
Oct 17, 2021
Messages
43
Location
Southampton
Car
S211 E220 CDi OM646 Evo
Hi All,

My first post so go easy! I have scanned through the various threads but wanted to pose some questions. I have just purchased a 2009 S211 E220cdi and I'm very happy with it but the rear park distance isn't working, just 4 solid red LED'S on the rear view display, I checked for codes using icarsoft MB v2 but no faults found. I found an old Bosch sensor in the credit card tray so looks like somebody has been tinkering in the not too distant past.

Q1. I am suspicious of the Thule tow bar and associated electrics as from what I have read these when installed are coded to disable the rear sensors or is that only when towing?

Q2. I don't intend to tow anything (ever) so can I unplug the tow bar electrics from rear SAM unit without any harm being done (obviously disconnecting batt neg before doing so)?

Q3. is it true you can fault find duff rear sensors by placing your finger on them to feel pulse/vibrations?

Any advice on removing tow bar electrics and solving the pdc issue are welcomed!!

Thanks guys

Chris
 
Hi All,

My first post so go easy! I have scanned through the various threads but wanted to pose some questions. I have just purchased a 2009 S211 E220cdi and I'm very happy with it but the rear park distance isn't working, just 4 solid red LED'S on the rear view display, I checked for codes using icarsoft MB v2 but no faults found. I found an old Bosch sensor in the credit card tray so looks like somebody has been tinkering in the not too distant past.

Q1. I am suspicious of the Thule tow bar and associated electrics as from what I have read these when installed are coded to disable the rear sensors or is that only when towing?

Q2. I don't intend to tow anything (ever) so can I unplug the tow bar electrics from rear SAM unit without any harm being done (obviously disconnecting batt neg before doing so)?

Q3. is it true you can fault find duff rear sensors by placing your finger on them to feel pulse/vibrations?

Any advice on removing tow bar electrics and solving the pdc issue are welcomed!!

Thanks guys

Chris
Q1 If installed correctly, sensors are disabled only when towing. However if the towball is in the way of the beams, it will give you 4 reds.
Q2 That should be OK.
Q3 Probably best to get the codes read.

Ernie
 
Q1 If installed correctly, sensors are disabled only when towing. However if the towball is in the way of the beams, it will give you 4 reds.
Q2 That should be OK.
Q3 Probably best to get the codes read.

Ernie
Thanks Ernie, sorry for the delayed reply.

Sensors all sorted now. I purchased 4 x Ridex sensors from Autodoc, plugged them in and now working perfectly. There was odd part numbers on some of the old ones so took a punt on a new set which cost the same as just 1 of the Bosch OEM's.
 

Users who are viewing this thread

Back
Top Bottom