So it looks like the car has decided to get grumpy with me. 2012 mk3 with BLIS.every now and then I get the error message on the dash saying there's an issue with the right hand side radar and it requires fixing. Thing is if I go into the menu and switch the system off and on the fault clears and it stays like this for ages until it throws its toys out the pram again. Switching car on and off also clears it. Only managed to get fault code once and that pretty much said right hand radar problems. The car is clean so can't be that, had my head under the back bumper and both Radar units are clean and wiring looks ok but that's all of done. Is this a known issue which needs a software update or is this the start of a failing radar unit?

What was the fault code? I have a workshop manual for the Edge BLIS system I can't imagine there will be too many differences between that and yours if you have a code i an try and see what they say in Diagnostic and Testing section (which runs to 35+ pages for BLIS alone)

===SODR DTC U3000:48-28===
Code: U3000 - Control Module

Additional Fault Symptom:
 - Supervision Software Failure

Status: 
 - Previously Set DTC - Not Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Side Obstacle Detection Control Module - Right

A defective BLIS radar module is not uncommon. Considering the rarity of the BLIS system on the Focus MK3 the failure rate is pretty high. The U3000 (Control Module Failure) DTC code combined with a software related Additional Fault Symptom basically means that the BLIS module has a software related internal fault. 

If there are software updates available for the Left (SODL) and Right (SODR) radar modules it is recommended to have the software of these modules updated to the latest software versions to start with. If there are no software updates available or a sotware update does not solve the problem the SODR module needs to be replaced to solve the problem. A new radar module will cost approximaltely 500 Pounds from Ford. 

From the Manual there are 4 x U3000 codes:

Sod's Law there is no reference to U3000 - 48

All the other codes refer to changing the detection module and are worded the same as this for 49

Quote

U3000:49 Control Module:
Internal Electronic
Failure
CLEAR the SODL or SODR Diagnostic Trouble Codes (DTCs) and REPEAT
the self­test. If the continuous memory or on­demand DTC U3000:49 returns,
INSTALL a new SODL or SODR. 
REFER to: Side Obstacle Detection Control Module (419­04 Side and Rear
Vision, Removal and Installation).

 

Ok. I cleared dtc's, reset the SODR but not the SODL. Drove for about 20 miles and fault returned. Disabled the BLIS in the dash menu then switch it back on it starts to work again. I'd just ignore it but car is used for driving instruction and I'm not allowed to present the car for test with any kind of warning lamp illuminated 

Picture of the unit. Both left and right carry same part number. I've found some but they finish AF instead of AE. Does the 2 last numbers make a difference?

I don't know whatthe significance of the suffix letters AE and AF are but like you I suspect they are on the same modules

From the little I have gleaned on the topic of BLIS the modules are VIN specific and will need to be programmed to your car so you will need a scanner that can do that - FORSCAN??

I have not found any other repairs - replacing the module seems to be the only option

Would it be worth swapping your modules around to see if the problem moves - at least then you would know it is a faulty module

That is an excellent idea. I'll do that first and mean time I'll ask on the Forscan forum if it's doable