The automobile meaning of the C1505 Code is found online and this is general meaning. Do not follow this general meaning for solving the car engine problem but you can learn some information about the code in general. The code meaning 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. 0 for IC Circuit High Voltage and 5 for Park/Neutral Position (PNP) Switch Circuit Engine Torque Signal Circuit. The code has started with the C letter and it means that chassis of the engine has the problem and it is easy to solve.