P0481 - COOLING FAN RELAY 2 CONTROL CIRCUIT

The DTC code P0481 has to do with the motor cooling fan circuit. When the vehicle is running, the necessary amount of air passing through the radiator effectively cools the engine but when the vehicle stops, there is no air passing through the radiator because the temperature starts to rise.

The Coolant Temperature Sensor (ECT) gives a signal to the Powertrain Control Module, which can detect the increase in the engine temperature. As soon as the temperature is in  its maximum level, which varies by the vehicle manufacturer, the PCM commands a relay to start the fan.

If there is a problem within this circuit that stops the appropriate function of the fan, it causes the motor to overheat when driving at low speeds or when stopped, this fault code is set.

• Malfunction Indicator Light (MIL).
• As soon as the engine stops, the temperature starts to rise.
• Engine overheating.

The reasons to establish the diagnostic code P0481 OBDII are

• The number two fan control relay may be faulty.
• Fan control relay two wires may present some faults that cause a short circuit.
• Poor electrical connections of the relay.
• The cooling fan is defective.
• Problems in the wiring of the cooling fan.
• Deficiencies in the fan connections.
• Sensor Engine Coolant Temperature (ECT) in bad conditions.

To solve the failures of the DTC code P0481 OBD2, you can do this:

• Check the TSB (Technical service bulletins). The solution to your problem may be known by the vehicle manufacturer.
• Check the fan and see if the radiator blocking the airflow is unobstructed. Turn the fan manually, if not, because the fan bearings are tripping, change the fan.
• Check the electrical connections of the fan. Make sure there are no corroded or burned wires. Do the same with the terminals of the connectors, repair, or change.
• Changes the cooling fan relay.