Ok so scanned the fl2 with my icarsoft v2 LR.. Came up with a U3002 code against the rear differential module... Google has drawn a blank for this..

Anyone seen this before? I was thinking the diff may have been changed before I bought the car? 🤔🤔

Don't think the rear diff has a sensor or electrical connection to throw a code. I understand U codes are communication errors sometimes spurious. Just wondering is your battery fully charged?

Didn't think it had.. Then thought maybe it was linked to the haldex.. But I imagine I would throw its own code up... Battery is grand only replaced 2 years ago and has good voltage running through it...

Just to confirm - the rear diff is entirely mechanical and definitely has no electrical parts. Jules

From FL2 Repair Manual

U3002-55Vehicle Identification Number (VIN)
Not configured Re-configure the relevant module as new using the manufacturer approved diagnostic system and re-test. If DTC remains install a new module, refer to the new module installation note at the top of the DTC Index

U3002-81Vehicle Identification Number (VIN)
Vehicle/component mis-match. Corrupt VIN data being transmitted, module previously installed to other vehicle
Install original module, check for DTCs and refer to relevant DTC Index

U3002-81Vehicle Identification Number- invalid serial data received
Incorrect Differential Electronic Module (DEM) installed to vehicle
Check and ensure the correct Differential Electronic Module (DEM) is installed. Check and install a new Differential Electronic Module (DEM) as required. Refer to the Warranty Policy and Procedures manual, or determine if any prior approval programme is in operation, prior to the installation of a new module/component.

Electronic differential control module
High speed CAN bus
Controls the operation of the electronic differential Mounted on front of rear differential
 FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 76k+ miles) (MY2015)