Tom demonstrates live ignition system diagnostics on a 1991 Honda Civic 1.5 DPI using a four-channel scope to simultaneously monitor the IC control signal, TDC sensor, crankshaft position sensor, and coil current.

The demo covers intentionally induced failures to observe how the PCM responds to the loss of each sensor signal, including:

• Killing the TDC sensor and observing ignition disruption behavior
• Killing the crankshaft sensor and comparing the PCM's response
• Simulating brief intermittent signal dropouts to show how minor disruptions may or may not affect engine operation

The session also covers techniques for capturing intermittent failures to hard drive for later review and analysis, and wraps up with practical notes on working with fewer than four channels.