I can’t make an accurate judgment without seeing the car and not knowing the specific situation. But my feeling is that there may be something wrong with your car itself, which is causing the air conditioning to be ineffective. You go to get your car repaired, turn off the engine and restart the trip computer. Only then does the recognition code display EPC.
Generally speaking, there are several possibilities for the EPC light to be on. The most common thing is that the throttle valve is dirty and should be cleaned. If there is a problem with the oil, the EPC fault light will also come on. Some Volkswagen models will also cause EPC alarms because the brake lights do not light up, and the brake switch and wiring need to be checked. Of course, there are also false positives and false positives from computers. EPC itself faults will all light up.
The car can start but won’t start? What is this glitch?