This module walks through a real-world diagnostic case on a 2011 Jeep Grand Cherokee 5.7L V8 presenting with a cylinder 2 misfire that persisted after spark plug and coil replacement. The case demonstrates how PicoScope can be used to go beyond basic code reading and identify a mechanical root cause — in this case, a worn exhaust cam lobe.

Key concepts covered include:

• Relative compression testing using starter motor current waveforms
• Identifying cylinders within a cranking pattern using ignition coil primary current as a reference
• Determining companion cylinders from the firing order
• Using dual WPS pressure transducers to simultaneously compare a suspect cylinder against a known-good cylinder, both cranking and running
• Overlaying waveforms using reference traces and time delay offsets to align companion cylinder signals for direct comparison
• Interpreting in-cylinder pressure waveforms to identify abnormal valve events