Possible Cause

NOTE:  The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

• Rear secondary HO2S (bank 1, sensor 2) heater failure
• Rear secondary HO2S (bank 1, sensor 2) SO2HT B1 line open
• Rear secondary HO2S (bank 1, sensor 2) SO2HT B1 line short to ground
• Rear secondary HO2S (bank 1, sensor 2) heater power supply line open (includes fuse blown)
• Rear secondary HO2S (bank 1, sensor 2) heater internal circuit open
• Poor ignition switch
• PCM internal circuit failure