Conditions for Clearing the MIL/DTC

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. 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
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 cooling fans for proper operation. Are the engine cooling fans operative?	Go to Engine Overheating	Go to Symptoms - Engine Cooling