Conditions for Clearing the MIL/DTC

WARNING: This page is about a different car, the 2007 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.

The PCM will turn the MIL OFF after 3 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
1	Was the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Check the engine cooling fan for proper operation. Is the engine cooling fan operative?	Go to Engine Overheating	Go to Symptoms - Engine Cooling