DTC P0139: Notes
DTC P0139 DETECTION CONDITION AND POSSIBLE CAUSES
| DTC P0139 |
Rear HO2S circuit problem |
| DETECTION CONDITION |
- The PCM monitors the rich (0.4 V
) to lean (0.3 V
) response time of the rear HO2S. The PCM measures the response time when the following conditions are met. The PCM determines that the rear HO2S response deteriorated when the measured response time is more than the threshold value (130 ms
) five consecutive times.
MONITORING CONDITIONS
- HO2S heater, HO2S, and TWC Repair Verification Drive Mode or EGR, HO2S heater, HO2S, TWC, and EVAP System Repair Verification Drive Mode
- The following conditions are met:
- Fuel cut during deceleration
- Engine speed is more than 500 RPM.
- Engine coolant temperature is more than 70°C {158°F}.
- HO2S (rear) output voltage is more than 0.4 V.
- The PCM monitors for a time-out malfunction (when rear HO2S remains above 0.3 V
for longer than a specified period of time during fuel cut control). The PCM measure the amount of time from when the following conditions are met until the rear HO2S output voltage drops below 0.3 V
. The PCM determines that a HO2S time-out malfunction has occurred when the detected time is more than the threshold value (6.4 s
) three consecutive times.
MONITORING CONDITIONS
- HO2S heater, HO2S, and TWC Repair Verification Drive Mode or EGR, HO2S heater, HO2S, TWC, and EVAP System Repair Verification Drive Mode
- The following conditions are met:
- Fuel cut during deceleration
- Engine speed is more than 500 RPM.
- Engine coolant temperature is more than 70°C {158°F}.
- HO2S (rear) is activated (more than 0.55 V)
.
Diagnostic support note
- This is an intermittent monitor. (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.
- DIAGNOSTIC MONITORING TEST RESULTS is available.
- PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle.
- FREEZE FRAME DATA is available.
- DTCs are stored in the PCM memory.
|
| POSSIBLE CAUSE |
- Rear HO2S deterioration
- Rear HO2S malfunction
- Rear HO2S looseness
- 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 delivery pipe to fuel pump
- Exhaust system leakage
- Purge solenoid valve malfunction
- Improper connection of purge solenoid hoses
- Insufficient compression
- Engine malfunction (Leakage engine coolant)
|