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)
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.
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)
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