It depends how good the info the ecu is getting,because its a safety feature it will try to give any functionality it can.Try the car on gravel or mud,you should still get ABS on the other 3 wheels.
Just be aware that in rare cases a new sensor wont fix it,I have seen cases where a new ecu was needed,the original just wasnt reading the sensor,even though it was giving a good output.
Here at LandyZone we have plenty of very knowledgable members so if you have any questions about your Land Rover or just want to connect with other Landy owners, you're in the right place.