P0139 - O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
DTC DESCRIPTION P0139 - O2 SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 2)
| Description: | The heated oxygen sensor (HO2S) monitor tracks the rate of voltage change during the rise and fall of the heated oxygen sensor bank 1, sensor 2 (HO2S12) signal. When the rate of voltage change is less than a calibrated value, the PCM begins to modify the fuel trim attempting to increase the HO2S voltage switch rate. This DTC sets when the PCM is at the allowable limit or has exceeded an allowable length of time for fuel trim modification, without detecting an acceptable rate of voltage change. | ||
| Possible Causes: |
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| Diagnostic Aids: | Access the HO2S test results from the Generic OBD II menu to verify the DTC. | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | GO to Pinpoint Test DW. | ||