Why can't the old Jetta EPC fault light refuel?

Why can't the old Jetta EPC fault light refuel? Old Jetta (check the transaction price | model details) Why is the EPC fault light on and can't refuel? Jetta EPC lamp can't refuel, which is caused by engine failure, usually throttle or harness failure. If this problem occurs, it must be repaired in time. The following is the introduction of engine and EPC: 1. Engine carbon deposit: When the engine is working, if the fuel in the engine is not completely burned, carbon deposit will appear at the throttle position, which will cause the indicator light to light up and increase the fuel consumption of the vehicle. 2.EPC indicator light: When the EPC indicator light is on, first clean the air intake system of the engine. It should be noted that the fuel used in the car must meet the fuel label of the engine. In the process of using the car, it is necessary to maintain the car regularly and clean up the carbon deposit on the accelerator regularly. @20 19