The meaning of the engine C1511 Code is available online but you should follow the automobile or general meaning of the code. The automobile meaning of the code is general information of the car engine problem and if you follow the general meaning, new problems may started. The general meaning of the code is C for Chassis Code Problem is controller area network wiring bus and modules. 1 for MFG – Manufacturer Specific. 5 for Computer And Auxiliary Outputs. 1 for Low Coolant Circuit and 1 for TFP Valve Position Switch-Drive Without Drive Ratio. The real meaning of the code is linked to the car manufacturer.