Misfire - verb
Definition of misfire
1. to have the explosive or propulsive charge FAIL TO IGNITE
2. to fail to fire
3. to miss an intended effect or objective
When it comes to Misfires. What does that mean? Often it is interpreted as a COMPLETE loss of combustion within a specific cylinder. That is not always the case. Most engine control modules are analyzing the acceleration of the crankshaft speed via a crankshaft position sensor and comparing each cylinders contribution to an expected value. When a cylinder is not contributing an expected acceleration to the crankshaft, it will set a misfire count within mode 6 data. When enough misfires have occured, a misfire related code will be set. This does not neccessarily mean that combustion did not happen . It simply means the crankshaft did not accelerate as expected.

Brin is tasked with diagnosing a rough running condition on a 2006 Honda Odyssey. He understands that it's best to follow Jim Morton's GENERAL TESTING before performing a pinpoint testing strategy but sometimes the data alone gathered during the general testing phase is not enough. Sometimes we might need to trust our instincts and experience and move to pinpoint test to find the answers.
In this video, Brin finds the route cause of the concern but uses a combination of experience, scan tool data acquisition and scope test to get the finish line.