OBD II Misfire And Diagnosis
When diagnosing misfires, it’s important to use tools that allow you to go beyond a simple code reader that displays a P03XX. Even an OEM-level scan tool can’t tell you what the firing voltage is or what the ignition pattern looks like. Nor can it tell you if the serial data is accurate or correct. For that kind of information you need a DVOM or a graphing multimeter/oscilloscope that can look at sensor voltages directly and display primary and secondary ignition patterns.
Magneti Marelli Signs CAS To Distribute Diagnostic Scan Tools
Magneti Marelli Aftermarket offers high-quality vehicle diagnostics for major makes and models. Developed with technician needs in mind, these easy-to-use testers enable you to quickly identify, isolate and repair a variety of vehicle concerns.
Maximizing Tools: Unconventional Diagnostic Methods, Part III
By thinking “outside the box” and using our tools to their fullest potential, we can diagnose more of the perplexing problems without spending an undue amount of time on them. In this article, our writers conclude this popular three-part series of Unconventional Diagnostic Methods, with more time-saving techniques.
Maximizing Tools: Unconventional Diagnostic Methods, Part II
In this second installment, Riverland Technical and Community College Instructors Olle Gladso, Vladimir Postolovskyi and Andrew Bezhanov provide more unconventional diagnostic procedures to try with your digital mulitmeter.
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.
Servicing Wheel Bearings And Wheel Speed Sensors
If you are replacing a wheel bearing on a late-model vehicle, you will be dealing with a wheel speed sensor. In the past decade, wheel speed sensors have been moving from differentials, axles and knuckles to inside or on the wheel bearing or hub unit. At this location, the sensors are more accurate and often more protected from the elements.
Tech Feature: Hall Effect Sensor Diagnostics
Hall effect crankshaft position (CKP) and camshaft position (CMP) sensors are critical components of an engine management system. The inputs they provide enable the powertrain control module (PCM) to determine engine speed and position including where a given cylinder is within the four-stroke cycle.
Tech Tip: Coil-On-Plug Misfire Diagnostic Tips for Ford/Lincoln/Mercury Engines
The misfiring cylinder must be identified through Self-Test misfire codes or through WDS Power Balance. Rule out base engine problems; rule out fuel problems; and then look at ignition problems (be sure to rule out coil primary circuit issues).
Mercedes: Diagnosing a P0301 Misfire Code Harnessing the Benefits of an Amp Probe
Electronics Diagnostic Specialist Sergio
Turbocharger Technology Continues to Improve
With the ability to increase fuel economy by up to 20% on gas vehicles and up to 40% on diesel vehicles, manufacturers have resorted to turbochargers to compensate for lowered engine displacement. Additionally, the improvements on turbocharging technology have increased the number of turbocharged vehicles on American roads. Some turbocharger manufacturers have even projected the number of turbocharged vehicles in the U.S. to quadruple in the next five years.