Conditions For Running The DTC

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

DTCs P0005, P0148, P0191, P0192, P0193, P0611, P1020, P1021-P1028, P1209, P2146, or P2665 are not set.
The ignition voltage is 6-18 volts.
CNG operation is not inhibited.