DTC P0137, P0157: Notes

• The PCM monitors input voltage from rear HO2S. If the input voltage from the rear HO2S sensor is below 0.1 V for 41.6 s  the PCM determines that circuit input is low.

  MONITORING CONDITIONS 

  • HO2S, HO2S heater and TWC repair verification drive mode
  • Following conditions are met.
    • Engine speed is above 1,500 rpm. 
    • Engine coolant temperature above 70 °C {158 °F}. 
    • Fuel injector control in rear HO2S 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 even exceed 0.1 V  though the short term fuel trim is controlled up to 25%  for 9.6 s  , the PCM determines that sensor circuit input is low.

MONITORING CONDITIONS 

• HO2S, HO2S heater and TWC repair verification drive mode
• Following conditions are met for above 32 s 

• Engine speed is above 1,500 rpm. 
• Engine coolant temperature is above 70 °C {158 °F}. 

Diagnostic support note 

• This is a continuous monitor (HO2S).
• MIL illuminates if 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.
• DTC is stored in the PCM memory.

• HO2S (Rear, RH) malfunction
• Short to GND in wiring between HO2S (Rear, RH) terminal A and PCM terminal 44
• Open circuit between HO2S (Front, RH) terminal A and PCM terminal 44
• Open circuit between HO2S (Front, RH) terminal B and PCM terminal 20
• HO2S (Rear, LH) malfunction
• Short to GND in wiring between HO2S (Rear, LH) terminal A and PCM terminal 45
• Open circuit between HO2S (Front, LH) terminal A and PCM terminal 45
• Open circuit between HO2S (Front, LH) terminal B and PCM terminal 20
• PCM malfunction