Opel Corsa D A14XER, ABS not working, warning light on the dashboard.
After starting the engine to warm it up in winter without driving, the ABS symbol on the dashboard lit up after a while. The wire from the ABS module connector to the front right wheel didn't ring as a contact. When the sensor rings, there's a signal and it's working properly. The verdict: a broken wire.
Error codes when reading: C1222; C0040.