P0138 Ford

Ford P0138 OBD-II Trouble Code Definition:

P0138 HO2S12 Circuit High Voltage

P0138 Ford OBD-II Trouble CodeDescription:

OBD Trouble Code P0138
O2 Sensor Circuit High Voltage
What does the code mean? OBD-ii Code P0138 definition:
The Heated Oxygen Sensor (2) located rear of catalytic converter produces an output signal relative to oxygen storage capacity of catalytic converter. Ho2S 2 signal is less active than signal produced by front oxygen sensor. This code sets when HO2 Sensor voltage is greater than 999 mV for more than 2 minutes (time depends on model. Could be as high as 4 minutes)
Symptoms Sumptoms of OBD code P0138
There may be no noticeable symptoms except for MIL illumination. Possible high fuel pressure can over rich the system.
Causes Causes of the OBD-II code P0138
A code P0138 may mean that one or more of the following has happened: Faulty O2 sensor Short to battery voltage in O2 sensor signal circuit High fuel pressure (not as likely)
Solutions Here are some potential solutions: Replace O2 sensor Repair short to battery voltage in o2 sensor signal circuit