The oil light may come on when the brakes are applied if the oil level is low. When the oil level is low, the oil pump may not be able to circulate enough oil to the engine, causing the oil pressure to drop and the oil light to come on.
Oil Pressure Sensor Malfunction:
A faulty oil pressure sensor can also cause the oil light to come on when the brakes are applied. If the oil pressure sensor is not functioning properly, it may not be able to accurately sense the oil pressure, causing the oil light to come on even though the oil pressure is normal.
Brake Booster Vacuum Leak:
A vacuum leak in the brake booster can also cause the oil light to come on when the brakes are applied. When the brake booster vacuum hose is leaking, it can cause the engine to run lean, which can in turn cause the oil pressure to drop and the oil light to come on.
Faulty Oil Pump:
A faulty oil pump can also cause the oil light to come on when the brakes are applied. If the oil pump is not functioning properly, it may not be able to circulate enough oil to the engine, causing the oil pressure to drop and the oil light to come on.
Worn Engine Bearings:
Worn engine bearings can also cause the oil light to come on when the brakes are applied. When the engine bearings are worn, they can allow oil to leak out of the engine, causing the oil pressure to drop and the oil light to come on.
