DTC P0137: Notes
DTC P0137 DETECTION CONDITION AND POSSIBLE CAUSES
| DTC P0137 |
Rear HO2S circuit low input |
| DETECTION CONDITION |
- The PCM monitors the input voltage from the rear HO2S. If the input voltage from the rear HO2S sensor is below 0.1 V
for 41.6 s
, the PCM determines that the circuit input is low.
MONITORING CONDITIONS
- HO2S, HO2S heater and TWC repair verification drive mode.
- The following conditions are met.
- Engine speed is above 1, 00 RPM.
- Engine coolant temperature is above 70°C {158°F}.
- Fuel injector control in rear HO2S is in closed loop control.
- The PCM monitors the input voltage from the rear HO2S when the following conditions are met. Under the following monitoring conditions, if the input voltage from the rear HO2S does not exceed 0.1 V
through the short term fuel trim is controlled up to 20.5%
for 9.6 s
, the PCM determines that the sensor circuit input is low.
MONITORING CONDITIONS
- HO2S, HO2S heater and TWC repair verification drive mode.
- The following conditions are met for more than 20.8 s.
- Engine speed is more than 1, 00 RPM.
- Engine coolant temperature is more than 70°C {158°F}.
Diagnostic support note
- This is an intermittent monitor. (HO2S)
- MIL illuminates if the PCM detects the above malfunctioning 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 PCM detects the above malfunction conditions during first drive cycle.
- FREEZE FRAME DATA is available.
- DTCs are stored in the PCM memory.
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| POSSIBLE CAUSE |
- Rear HO2S malfunction
- Open circuit or short to ground in wiring between rear HO2S terminal A and PCM terminal 1Y
- PCM malfunction
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 Courtesy of MAZDA MOTORS CORP.
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