The B2166 Code explains the real problem of the engine and it is necessary thing if the car problem is necessary to solve. The dictionary meaning of the code is general meaning. The B2166 OBD 2 code on cars with electronically measured automatic transmissions, the 3-4 shift solenoid is accountable for actuating the hydraulic circuits to trigger clutches or bands that alteration gears confidential the automatic broadcast. There are now 2 chief types of cylinder deactivation used today, dependent on the type of engine. The B2166 code for the pushrod plan which usages solenoids to change the oil compression transported to the lifters.