The common meaning of the U1018 Code is automobile dictionary meaning what is available online and it is not very serving content for your car engineer for solving the car engine. You need to assemble the real automobile dictionary meaning from the automobile manufacturer. The U1018 engine code looks a kind of network problematic. The general/automobile meaning of the code is U means Network Code Problem is climate control system, lighting, airbags, etc. 1 means MFG – Manufacturer Specific. 0 means Fuel And Air Metering .1 for Low Coolant Circuit and 8 for PCM Stack Overrun. Do not drive the car until the problem from the car engine.