The engine P1879 code on cars with electronically measured automatic shows, the 3-4 shift solenoid is accountable for activating the hydraulic circuits to trigger clutches or bands that modification gears inside the automatic show. The automobile engine must check the car engine manually to know the right cause of the car engine problem. Otherwise, it becomes difficult to solve the car engine problem. The automobile dictionary meaning of the code is easily found from online and it is very important thing if the right meaning of the code is not found. The right meaning of the code should be used if it is found.