DTC P0139:00: Notes

DTC P0139:00 (MZR 1.5) DETECTION CONDITION AND POSSIBLE CAUSES

DTC P0139:00	HO2S circuit slow response
DETECTION CONDITION	The PCM monitors the rich (0.45 V) to lean (0.25 V) response time of the HO2S. The PCM measures the response time when the following conditions are met. The PCM determines a HO2S response deterioration malfunction when the measured response time is more than 160 ms for 2 of 3 times . MONITORING CONDITIONS Drive Mode 03 (EGR System, A/F Sensor Heater, HO2S Heater, A/F Sensor, HO2S and TWC Repair Verification Drive Mode) The following conditions are met: During deceleration fuel cut Estimated temperature of the zirconia element inside the HO2S: above 450 °C {842 °F} The PCM monitors for a time-out malfunction (when HO2S remains above 0.2 V for longer than a specified period of time during fuel cut control). The PCM measures the amount of time from when the following conditions are met until the HO2S output voltage drops below 0.2 V . The PCM determines a HO2S timeout malfunction when the detected time is more than 4 s for 2 of 3 times . MONITORING CONDITIONS Drive Mode 03 (EGR System, A/F Sensor Heater, HO2S Heater, A/F Sensor, HO2S and TWC Repair Verification Drive Mode) The following conditions are met: During deceleration fuel cut Estimated temperature of the zirconia element inside the HO2S: above 450 °C {842 °F} Diagnostic support note This is an intermittent monitor (A/F sensor, HO2S). The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle. FREEZE FRAME DATA (Mode 2)/Snapshot data is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	HO2S looseness Exhaust system leakage Fuel supply system malfunction or improper fuel line pressure Fuel leakage in fuel line between fuel distributor and fuel pump Restricted fuel filter (built-into fuel pump unit) Pressure regulator malfunction (built-into fuel pump unit) Fuel pump malfunction Purge solenoid valve malfunction Engine internal malfunction Engine coolant leakage to combustion chamber Insufficient engine compression HO2S malfunction HO2S deterioration PCM malfunction