The key to efficient driveability diagnostics is to make easy-to-perform analyses by limiting hands-on testing time under the hood and without disassembly. This allows you to decide what is “good” on the vehicle so you can focus on the remaining potential faults when it is time to test. This is usually best accomplished by obtaining driveability data right from the driver’s seat. Utilizing a scan tool tends to yield us as diagnosticians what we need to make preliminary decisions about what system may be faulted and the driving conditions in which the fault surfaces. So, how do we handle locating the suspect cylinder when it comes to the intermittent misfire concern? Well, the Autel MS919 has you covered there.
Join Motor Age Technical Editor Brandon Steckler as he leverages the power of the Autel MS919 to perform a scan tool enhanced function mimicking that of the Ford factory scan tool platform, the Ford Power Balance Test. The test leverages the variation in crankshaft speed (as reported by the CKP sensor) and correlates it with the engine’s firing order and cylinder position. The combination of the acquired PCM inputs allows the ford Power Balance Test to indicate not only if a misfire is present, but also which cylinder is misfiring and whether it is intermittent.
The easy-to-view graphical data allows the scan tool to plot a live misfire data trace in the color blue (representing current crankshaft speed variations). The Ford Power Balance Test in the Autel MS919 will also provide a historical trace of crankshaft variations, in the color gray. This allows us to see if a misfire is present or has come and gone. It’s a great way to begin a misfire analysis on a Ford vehicle and is carried out obtaining data right from the DLC with no need to even open the hood. This allows the technician to gain insight right from the driver’s seat! Tune in to this episode of “The Trainer #147” and see just how powerful this factory-level enhanced scan tool function can be and how easy it is to perform!
