The car engine is an important thing and finding the correct meaning of the C1503 Code is necessary for solving the car engine problem. This code becomes visible for the car engine is tested. The general meaning of the code is available online and for this 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. 0 for IC Circuit High Voltage and 3 for Transmission Control Module Reprogrammable Memory. Do not follow this general meaning of the code for solving the car engine, it is not suitable.