Code Enable Criteria

• ECM has learned a minimum noise level at idle for 5 seconds and does not detect a change in noise level between 2500-3500 RPM for 5 seconds.
• Engine run time is more than 10 seconds.
• ECT is more than 104°F (40°C).
• Engine speed is more than 2000 RPM.
• No ECM internal failure DTCs are set.

DTC sets when ECM detects knock sensor 1 signal is less than a certain threshold (based on engine load and speed).