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 (sensor 2) SO2HTB1 line short to ground
• Rear secondary HO2S (sensor 2) SO2HTB1 line open
• Rear secondary HO2S (sensor 2) heater power supply line failure
• PCM internal circuit failure