Emission control systems have specific legislation called On Board Diagnostics (OBD). To comply with emission requirements, a significant part of the engine control module (ECU) software is related to OBD, and various validation tests are required for all its functions. These tests are mostly conducted on prototype vehicles or complex test benches such as Hardware-in-the-Loop (HiL).In an effort to reduce operational costs and increase efficiency, vehicle manufacturers are seeking alternatives to minimize the demand for prototype vehicles during the project development phase. The need for new validation methods that contribute to this has led to the use of computational models. Examples of these methods include the use of Software-in-the-Loop (SiL) with real-time simulations and automated testing routines.This study aims to develop a methodology to demonstrate faults related to the diagnosis of the fuel pump electronic module (PEM) using a process with automated routines to allow some of the tests currently executed on prototype vehicles or HiL benches to be performed in a virtual environment (SiL).