OBD Diagnostics for Engine Detonation and Knock Control

Engine knock, also known as detonation, occurs when fuel ignites prematurely inside the combustion chamber. Persistent knocking can severely damage pistons, valves, and bearings. OBD knock detection diagnostics continuously monitor combustion behavior to protect the engine.

What Causes Engine Knock

Low Fuel Quality

Low-octane fuel increases the risk of detonation.

Incorrect Ignition Timing

Excessive spark advance can cause early combustion.

How OBD Detects Knock

Knock Sensor Monitoring

OBD analyzes vibration signals produced by abnormal combustion.

Timing Adjustment Feedback

The ECU retards ignition timing when knock is detected.

Benefits of Knock Diagnostics

• Prevents engine damage

• Maintains power output

• Improves fuel efficiency

Conclusion

OBD knock diagnostics ensure safe combustion and long-term engine reliability.