Conditions for Clearing the MIL/DTC

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The PCM will turn the MIL OFF after three consecutive trips that the diagnostic has been run and passed.
The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P1258

Step	Action	Yes	No
Connector End View Reference: Cooling System Connector End Views
1	Was the Diagnostic System Check for Engine Cooling performed?	Go to Step 2	Go to Diagnostic System Check - Engine Cooling
2	Check the engine coolfans for proper operation. Are the engine coolfans operative?	Go to Engine Overheating	Go to Symptoms - Engine Cooling