DTC P0051-O2 Sensor 2/1 Heater Circuit Low: Notes

Fig 1: Sensor 2/1 Heater Circuit - Circuit Diagram

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article.

When Monitored:
Battery voltage above 10.6 volts, ASD is powered up, and O2 heater is on.
Set Condition:
Desired state does not match Actual state.

One Trip Fault. Three good trips to turn off the MIL.

Possible Causes
(K199) O2 2/1 HEATER CONTROL CIRCUIT SHORTED TO GROUND
O2 SENSOR
PCM