DTC P0137: 1/2 O2 Sensor Shorted To Ground: Description

The 1/2 HO2S is monitored at a cold start, when engine coolant temperature is less than 98°F (37°C), ambient/battery temperature sensor reading is within 27°F of engine coolant temperature and engine coolant temperature is more than 170°F (77°C) the last time ignition was on. DTC P0137 may be stored in Powertrain Control Module (PCM) if 1/2 oxygen sensor signal voltage is less than .156 volt for 28 seconds after engine is started. Possible causes are:

• Intermittent Condition
• Faulty 1/2 HO2S
• 1/2 HO2S Signal Circuit Shorted To Ground Or To Sensor Ground Circuit
• 1/2 HO2S Signal Circuit Shorted To Heater Ground Circuit
• Faulty Powertrain Control Module (PCM)