Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2002 Saturn Vue, 2002 Pontiac Montana, 2002 Pontiac Aztek, 2002 Oldsmobile Silhouette, and 2002 Oldsmobile Bravada. However, it is still accessible from the selected car via links, so may be relevant.
If glow plug relay is stuck in ON position, check for proper operation of glow plugs. When glow plugs are commanded ON by scan tool, an internal ECM timer protects glow plugs from damage by cycling them ON for 3 seconds and then OFF for 12 seconds. Most glow plug system failures are covered by DTC P0380. If no DTCs are stored, vehicle is hard to start, White smoke is present during cranking or after vehicle is started, the most likely cause of failure is glow plugs.