What is the cause of Jetta epc lamp failure?

The first one in Pacific Auto Network is that the brake lights don't work. When the brake light of our vehicle is not on, the EPC fault light will appear. The second is the throttle failure. If there is something wrong with the engine throttle or wiring, EPC will also light up. The fourth is that the clutch switch is broken. Like the brake switch, EPC will appear when the clutch switch is broken.

In the past, the driver controlled the accelerator pedal according to the power demand of the engine, and the accelerator pedal controlled the accelerator opening through a steel wire rope. In EPC system, the original accelerator cable is cancelled and replaced by the sensor of pedal device.

The engine control unit (ECU) calculates the optimal target throttle opening according to the position data fed back by the pedal sensor, and sends a signal to the throttle drive motor to rotate the throttle to this angle.

This method is superior to the pull-wire acceleration control, because the electronic throttle knows the power demand of the engine by calculating and analyzing the input signal of the accelerator pedal position, and converts this information into the torque of the engine through various actuators.

When the engine speed needs to be adjusted due to safety, fuel consumption and other reasons, the engine control unit can adjust the position of the throttle valve without using the accelerator pedal. The advantage of this structure is that the control unit can limit the position of the throttle according to various requirements.

(Photo/Text/Photo: Pacific Auto Network Qi Song He)