Conditions For Running The DTC

WARNING: This page is about a different car, the 2003 GMC Savana and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.

The CNG fuel tank pressure is more than 750 psi (5171 kPa).
The Engine Coolant Temperature (ECT) is more than 68°F (20°C).
The engine speed is more than 600 RPM.
The Mass Airflow (MAF) is less than 175 g/s.