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Use On-Board Diagnostics to Detect Misfire

This example shows how to introduce, detect, mature, and report misfire events from the SI Core Engine. The model demonstrates misfire on-board diagnostics (OBD) warnings.

Model

Run Simulation

On the Simulation tab, click Run. As the simulation runs, diagnostic trouble codes appear on the MIL Light display. P0300 is a general warning for a misfire issue in one or more cylinders. P0303 indicates a specific misfire issue with Cylinder 3.

ECU With TPU and Diagnostics

This subsystem detects misfire events, using crankshaft acceleration as an indicator. Navigate to autoblkSICoreOBDMisfire > ECU With TPU and Diagnostics > TPU Level Misfire Detection. Open the Diagnosis Parameters block. You can modify the OBD threshold calibrations for detection and maturation.

OBD Breakout Box

This subsystem defines misfire events to inject into the simulation. Navigate to autoblkSICoreOBDMisfire > OBD Breakout Box > Injector Pulsewidth Fault Injection. Open the Misfire Events block. You can modify the misfire fault injection timing.

Engine Plant With Sensors and Actuators

The SI Core Engine computes cylinder pressure as a function of crank angle. The Crank VRS Sensor and Measurement Circuit simulates the 58-tooth wheel that tracks the progression of the 4-stroke engine cycle.

Cranktrain block

Open the Cranktrain block to modify the engine cranktrain geometry and dynamics.

See Also