Because it can allow the engine to overheat.
Car cooling fan control circuit.
A switched terminal will be hot only when the key is on.
What causes the p0480 code.
On older fan circuits the thermostatic switch connects to battery power on one side and to the fan motor on the other.
The vehicle s pcm s function is to act as a ground to operate components not to supply power.
The ecu then triggers a check engine light to illuminate on the dashboard.
So now we have a wire that goes through the engine bay to the cabin of your car.
This will be the wire that connects your switch to your fan power wire.
The electric cooling fan uses a direct current dc electric motor with a thermo switch module or computer control to turn it on or off depending on coolant temperature or ac operating condition.
A constant power supply from the battery is present on a terminal in each of the relays.
P0480 means that the cooling fan 1 control circuit has a malfunction.
The fan relays are nothing but a remote light switch.
On applications that have variable fan speeds.
Which may not be fast enough to prevent overheating.
This one turns on the fan when the circuit is closed.
The fan may work but it only runs at low speed.
During the install christian shot.
Now take the power wire from your fan and connect it to the wire that is going through the firewall.
The engine may also overheat if fan speed fails to increase when additional cooling is needed.
The fan as well as other apparatus draws too much amperage to be safe in the cockpit so it s kept under the hood.
Or a failure of the fan relay or control circuit is bad news.
Engine cooling fan issues.