Conditions For Running DTC

WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Sierra, 2002 GMC Savana Special, 2002 GMC Savana Camper Special, and 2002 GMC Savana. However, it is still accessible from the selected car via links, so may be relevant.

DTC P1518 is not set.
The ignition switch is in the crank or run position.
The ignition voltage is greater than 6 volts.