DTC Detection Logic

The heated oxygen sensor 2 has a much longer switching time between rich and lean than the air fuel ratio (A/F) sensor 1. The oxygen storage capacity of the three way catalyst 1 causes the longer switching time. To judge the malfunctions of heated oxygen sensor 2, ECM monitors whether the maximum voltage of the sensor is sufficiently high during various driving conditions such as fuel-cut.

Courtesy of NISSAN NORTH AMERICA, INC.

DTC	CONSULT screen terms (Trouble diagnosis content)	DTC detection condition
P0137	HO2S2 (B1) (O2 Sensor Circuit Low Voltage Bank 1 Sensor 2)	Diagnosis condition	-
		Signal (terminal)	-
		Threshold	The maximum voltage from the sensor does not reach the specified voltage. ECM detects the heated oxygen sensor 2 circuit is short to ground.
		Diagnosis delay time	-