Sergio Fernandez, Author at UnderhoodService
Diagnosing A P0301 Misfire Code On A 2001 Mercedes-Benz E320 Sedan

Since the advent of OBD II, every vehicle is equipped with a sophisticated system that measures each cylinder’s contribution to engine power, becoming one of the most difficult challenges we face. Each time a cylinder fires, the misfire monitor uses a highly accurate crankshaft angle measurement to measure the crankshaft position. This system needs to have an accurate crankshaft position sensor that is able to read the crankshaft position, even at high RPM, sending a clear signal to the PCM. Then the PCM monitors the crankshaft acceleration time for each cylinder at the firing time.

BMW Feature: Understanding Variable-Capacity A/C Compressors

Diagnostic Specialist Sergio Fernandez discusses the ins and outs of the swash-plate compressor and how its variable cylinder displacement allows for the most efficient HVAC operation and boosts fuel economy.

Mercedes-Benz: Managing Misfires, Solving Those Strange, Intermittent Engine Vibrations

Automotive Electronics Diagnostician Sergio Fernandez discusses how to solve those strange, intermittent engine vibrations on a 2003 E320, with 3.2L V6 engine and 120,000 miles. The diagnosis begins with these findings: DTC P0305, misfire on cylinder #5; and DTC P0301, misfire on cylinder #1.