Fixing the SPN 973 FMI 13 Calibration Fault
Seeing spn 973 fmi 13 pop up on your diagnostic tool is enough to make any driver or fleet owner let out a heavy sigh, mostly because it involves your engine brake. If you're rolling down a steep grade with a full load and your Jake brake decides to take a nap, things get stressful pretty quickly. This specific code isn't usually telling you that something exploded; rather, it's a way for your truck's brain to say it's confused about where the engine brake actuator is sitting. ...