What does it mean when the DEF light in a car comes on?
1 Answers
The DEF light in a car coming on indicates a low level of coolant in the auxiliary tank, which can be caused by: 1. A leak in the cooling system or a minor issue with the cylinder head gasket; 2. Overheating of the coolant leading to a shortage in the system; 3. A seized water pump causing damage to the timing belt, which in turn affects the piston and valves; 4. A blown head gasket mixing coolant with engine oil or causing it to be expelled through the exhaust pipe. The auxiliary tank is part of the engine's cooling system and helps balance the pressure in the radiator. Maintenance methods include: 1. Stopping to check if the temperature rises too high while driving; 2. Immediately stopping to inspect if smoke is seen coming from the radiator; 3. Regularly replacing the coolant.