DTC Detection Logic

WARNING: This page is about a different car, the 2019 Nissan NV3500 HD and 2019 Nissan NV2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

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 switching response of the sensor's voltage is faster than specified during various driving conditions such as fuel cut.

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DTC	CONSULT screen terms (Trouble diagnosis content)	DTC detection condition
P0139	HO2S2 (B1) [Heated oxygen sensor 2 (bank 1) circuit slow response]	Diagnosis condition	--
		Signal (terminal)	Heated oxygen sensor 2 signal
		Threshold	The switching time between rich and lean of a heated oxygen sensor 2 signal delays more than the specified time computed by ECM
		Diagnosis delay time	--
P0159	HO2S2 (B2) [Heated oxygen sensor 2 (bank 2) circuit slow response]	Diagnosis condition	--
		Signal (terminal)	Heated oxygen sensor 2 signal
		Threshold	The switching time between rich and lean of a heated oxygen sensor 2 signal delays more than the specified time computed by ECM
		Diagnosis delay time	--