LEMON Manuals: Even more car manuals for everyone
Home >> Subaru >> 2005 >> Outback R VDC Limited >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 13 (Diagnostic Trouble Code (DTC) Detecting Criteria (H4SO U5 (PZEV))) >> Diagnostic Trouble Code (DTC) Detecting Criteria >> DTC P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) >> Diagnostic Method >> Abnormality Judgment

Abnormality Judgment

WARNING: This page is about a different variant/trim than selected.
  1. Judge NG when the judgment value is larger than the threshold value after fuel shut-off in deceleration.

    Response time (Diagnosis value) > Threshold value --> Abnormal

    NOTE: Variation time of rear oxygen sensor output voltage is short during fuel shut-off in deceleration. Carry out the NG judgment only after the fuel shut-off in deceleration. As for OK judgment, without the condition of fuel shut-off in deceleration, judge OK if the value is below the threshold value.

    Judge NG when the malfunction criteria below are completed in 2 seconds after the recovery of fuel shut-off in deceleration which requires 6 seconds or more.

  2. Judge NG when the O2 sensor voltage after recovery of fuel shut-off in deceleration is large. Judge NG when fuel shut-off in deceleration is also long (6s or more), and although carried out the fuel shut-off in deceleration cut return, when O2 sensor voltage is large (more than 0.55 V).

Judgment Value 

JUDGMENT VALUE

Malfunction Criteria Threshold Value
Shortest time change from rich (500 mV O2 output) to lean (300 mV) if voltage reduces from 550 mV to 250 mV. > 0.698 milliseconds
Or time when more than 550 mV > 2 seconds

Time Needed for Diagnosis:  Once

Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.



  1. Judge NG when the judgment value is larger than the threshold value after recovery of fuel shut-off in deceleration.

    Response time (Diagnosis value) > Threshold value --> Abnormal

  2. Judge NG when the O2 sensor voltage after recovery of fuel shut-off in deceleration is small.

Judgment Value 

JUDGMENT VALUE

Malfunction Criteria Threshold Value
Shortest time change from lean (300 mV O2 output) to rich (500 mV) if voltage reduces from 500 mV to 250 mV. > 2 seconds
Or longest time to change to 250 mV > 120 seconds

Time Needed for Diagnosis:  Once

Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.