P0137 O2 Sensor Circuit Low Input (Bank 1/Sensor 2): DTC Detecting Condition

Item	Detecting Condition	Possible Cause
DTC Strategy	Check short circuit to ground on rear HO2S	Short to ground in signal harness Contact resistance in connectors Faulty Heated O2 Sensor (HO2S)
Enable Condition	Catalyst temperature model > 400°C (752°F) No relevant failure 10 < Battery voltage < 16 Closed loop mode Lambda controller is not on the limit Catalyst purge after fuel cut off is not active
Threshold Value	Downstream O2 Sensor voltage < 0.02V & sensor element resistance < 30Ω
Diagnostic Time	20 sec.
Mil On Condition	2 Driving Cycles