Ford's engine trouble light is on and off sometimes. Why?

Engine fault light. Usually it appears for two reasons. First, the brake switch is broken. Second, the throttle needs cleaning.

The main reason why the engine fault light is on is that the throttle valve or the engine has too much carbon deposit, and the mixture ratio is out of balance after the oxygen sensor fails, which is easy to make the engine fault light on. This is related to cleaning the carbon pollution sensor caused by the throttle. If you drive at a low speed in the urban area for a long time, this phenomenon is easy to appear. It is possible that the insulation layer of high-voltage line is easy to break down after aging, which leads to the engine fault light. Because the self-diagnosis system of the control unit generally does not prompt the fault code of the high-voltage line, it is difficult to find similar problems when they occur.