Code 21
WARNING: This page is about a different car, the 1995 Dodge Pickup and 1995 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
DRB displays O2S STAYS AT CENTER. Condition is: no rich or lean signal detected from oxygen sensor input. DRB will display left or right O2S (if equipped).
DRB displays O2S SHORTED TO VOLTAGE. Condition is: oxygen sensor input voltage maintained at more than normal operating range. DRB will display left or right O2S (if equipped).