Another A6 Electric handbrake issue

Anyone shed some light. Handbrake packed up a few months ago. After changing pads. I have carista to wind back the callipers, however forgot to put battery charger, but battery is only a few months old. I had the intermittent not releasing problem before i changed pads.
The hand brake module no longer talks to the car ie there is no press footbrake messages no more, just a constant drone and big red sign. Have pulled fuses / disconnected battery etc.
Bought a second hand module, but i do not have vcds to do the basic function tests, is that necessary ? The second module did talk to the car, but now, its the same as the original, constant drone etc.
So thinking, as the main problem is the wiring harness. However when car is in motion, when its making its drone sound , when the switch is pulled up the handbrake works as an emergency brake???? So therefore it cant be wiring issue,as the calipers need power to operate the motors. Have also disconnected the module and tried the emergency brake and nothing.
Quite confused and getting desperate as mot is approaching .

over s certain speed the emergency brake is working the main brakes not the rear hand brake mech. is it a wiring thing? the main wires to feed the calipers maybe, not enough power getting to them? have you had a scan, any codes?

obd eleven an option?

The new handbrake module will need adapting to the car with VCDS before it will work.

I live in South Shields and have VCDS if you want to have a go at it, but I have no idea how to code in a new module.

As said above the replacement will need to be coded to the correct code for your car.

The functional test/calibration needs to done as you have wound the callipers back by handy you may have snapped the drive belt in one of the motors which could explain the noise.

As you said you have an emergency brake function I would suspect it just needs calibration and a fault code to be cleared.

That would be fantastic :) Dave52 I need to purchase another module, think i have damaged the second module, by plugging in unplugging, pulling fuses out etc.. have read that the modules are quite sensitive to the power it receives, that's why a battery charger is advised to be used when changing pads (must be down to a drop in current that damages them) Have also read that the module is plug and play, however does need the basic function test via vcds , was hoping that was not the case, seems to be that exactly. If someone could confirm this as correct... Audi A6 (4F) Parking Brake - Ross-Tech Wiki

callipers were wound back using carista . the drone noise is from the warning lights / dashboard inside the car, once past 5mph

You can contact me on 07905 766619 and we can arrange to meet.