When the same malfunction is detected and maintained during two sequential driving cycles, MIL will automatically light. MIL will go off automatically after 3 sequential driving cycles without the same malfunctions.
After the ECM first detects a malfunction, a diagnostic trouble code is recorded when the engine is restarted and the same malfunction is re-detected. However, for misfire and CKP sensor, diagnostic trouble codes are recorded on the first detection of the malfunction.
After recording the diagnostic trouble code, if the ECM does not re-detect the malfunction for 80 warm-up cycles, the diagnostic trouble code will be erased automatically from the ECM memory.