DTC P0139 [L3]: Notes
DTC P0139 (L3) DETECTION CONDITION & POSSIBLE CAUSES
| DTC P0139 |
HO2S circuit malfunction |
| DETECTION CONDITION |
- The PCM monitors the rich (0.4 V)
to lean (0.3 V)
response time of the HO2S. The PCM measures the y-response time when the following conditions are met. The PCM determines a HO2S response deterioration malfunction when the measured response time is more than the threshold value (80 ms)
five consecutive times.
MONITORING CONDITIONS
- A/F sensor heater, HO2S heater, A/F sensor, HO2S, and TWC Repair Verification Drive Mode
- Following conditions are met:
- During deceleration fuel cut
- Engine speed is above 500 rpm.
- Engine coolant temperature is above 70°C {158°F}.
- HO2S is activated (more than 0.55 V).
- 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 the threshold value (6 s)
three consecutive times.
MONITORING CONDITIONS
- A/F sensor heater, HO2S heater, A/F sensor, HO2S, and TWC Repair Verification Drive Mode
- Following conditions are met:
- During deceleration fuel cut
- Engine speed is above 500 rpm.
- Engine coolant temperature is above 70°C {158°F}.
- HO2S is activated (more than 0.55 V)
Diagnostic support note
- This is an intermittent monitor. (A/F sensor, HO2S)
- 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 the first drive cycle.
- DIAGNOSTIC MONITORING TEST RESULTS is available.
- FREEZE FRAME DATA is available.
- DTC is stored in the PCM memory.
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| POSSIBLE CAUSE |
- Looseness HO2S
- Leakage exhaust system
- HO2S deterioration
- HO2S malfunction
- Purge solenoid valve malfunction
- Purge solenoid hoses improper connection
- Pressure regulator (built-in fuel pump unit) malfunction
- Fuel pump malfunction
- Fuel filter (built-in fuel pump unit) clogged or restricted
- Fuel leakage on fuel line from fuel distribution pipe and fuel pump
- Engine malfunction (Leakage engine coolant)
- Insufficient compression
- PCM malfunction
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