See this repair guide
MINI 2002-05
Brake Pads
REMOVAL & INSTALLATION

http://www.autozone.com/.../...rGuideContent.jsp

It is possible.If the old sensor its worn and re-installed with new pads the light will be on.Check it first before u buy any parts.

You have to determine with of the two are must worn out if you have to chose one.
The brakes are a very important safety feature on a vehicle.
So depending the condition of the tire and if you have a back up spare tire, I will go for the brakes first.

Pictures are worth a thousand words. Click the link and scroll down

http://www.justanswer.com/.../...e-pads-front.html

"I am wondering if those sensors may have been disconnected when the brake work was done by the dealership?" It can be, and since you got it serviced in the "Stealership", my suggestion is to bring it back. Im sure it still has the warranty for the repair.

Worst case scenario

1. Check for any indication that the moisture has penetrated the ABS/ASC/DSC control unit or the connectors for the wheel speed sensors.

2. Replace the following parts if moisture is present in the connectors or if the connectors are corroded.

a. Control unit (Follow Repair Instructions 34 52 515 for Replacing ABS/ASC Control Unit or 34 52 516 for Replacing DSC Control Unit.)

b. Connector housing.
- 47-pin connector housing at the wiring harness for the ABS/ASC/DSC control unit, P/N 61 13 0 306 846.
- Female socket contacts (1.5 x 0.63 mm), P/N 61 13 0 306 845, with sealing sleeve, P/N 61 13 0 306 844.
- Female socket contacts (5.2 x 0.63 mm), P/N 61 13 0 146 396, with sealing sleeve, P/N 61 13 0 146 397.

c. Wheel speed sensors (replace only if corroded)
- 2-pin female socket housing at the wiring harness for the left and right wheel speed sensors, P/N 61 13 0 390 476.
- Female socket contacts (0.2-0.5 mm), P/N 61 13 0 030 855.
- Front left and right wheel speed sensors, P/N 34 52 6 756 384.
- Repair the wheel speed sensors by following ­Repair Instructions RA 34 52 525.

d. Terminal ring on the ABS ground pin.

Important note: When disconnecting the 47-pin and 2-pin connectors from the wiring harness, make sure that the female socket contacts are not removed from the housing. In addition, 1 cm of cable should remain on the female socket contacts and on the ground cable terminal ring. Replaced parts will be requested through the warranty system for analysis. Therefore, take care not to damage replaced parts during ­removal.

3. Apply dielectric contact grease, P/N 83 23 0 149 149, to the contact areas of the new connector to prevent future moisture penetration.

Just replace all brake pads and here's why:

Usually its the front that wears out first before the rear, so let's just change the front.......

after a couple of months the brake wear indicator lights up again, obviously its for the rear, so another purchase of pads and another install is in the works.

NOW, replace all four and it will take you years before it lights up again. You just saved time and money.

Autopartswarehouse.com "You just saved time and money, we here to make you save more"

Do you feel strange with your braking? Did you check already your brake fluid, maybe low? Do see any leak under the car near your tires while at park? Don't just jump into replacing the brakes if you’re not sure of what the warning light is exactly referring to. Check your owner's maintenance manual for the periodic maintenance of your brake or have it scanned by a scan tool for you to make sure (free scan can be obtain in some parts shops); by this it will save you time and money. By the way, brake pad replacement task can be done by you.

Hi there coopers, since you replaced the sensors, did you do continuity test from sensors to ECU? Signal should be the same at the ECU. Check also resistance of controller/modulator valve solenoids (equal valves).

Other than warning light is on, what other details did you observed? If brake assembly is the problem, do you feel brake dragging? noise(squeal)?