Diagnosing Nissan P030x Codes with the ECM by Nissan TechNews | Aug 15, 2011 | Driveability + Emissions Diagnosis, Engine Mechanical, Nissan, Nissan TechNews Features | 0 When a misfire is imperceptible, you may need to use the ECM as your “eyes†and “earsâ€. Learning to use freeze frame data and pending codes will speed diagnosis and reduce comebacks. Read More