DTC Detection Logic

WARNING: This page is about a different car, the 2018 Nissan NV3500 HD and 2018 Nissan NV2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

To judge malfunctions, this diagnosis measures response time of the A/F signal computed by ECM from the A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the compensated time (the A/F signal cycling time index) is inordinately long or not.

DTC	CONSULT screen terms (Trouble diagnosis content)	DTC detection condition
P014C	A/F SENSOR1 (B1) [Air fuel ratio (A/F) sensor 1 (bank 1) circuit slow response]	Diagnosis condition	-
		Signal (terminal)	Air fuel ratio sensor 1 signal
		Threshold	The response time of a A/F sensor 1 signal delays more than the specified time computed by ECM
		Diagnosis delay time	-
P014D	A/F SENSOR1 (B1) [Air fuel ratio (A/F) sensor 1 (bank 1) circuit slow response]	Diagnosis condition	-
		Signal (terminal)	Air fuel ratio sensor 1 signal
		Threshold	The response time of a A/F sensor 1 signal delays more than the specified time computed by ECM
		Diagnosis delay time	-
P015A	A/F SENSOR1 (B1) [Air fuel ratio (A/F) sensor 1 (bank 1) circuit delayed response]	Diagnosis condition	-
		Signal (terminal)	Air fuel ratio sensor 1 signal
		Threshold	The response time of a A/F sensor 1 signal delays more than the specified time computed by ECM
		Diagnosis delay time	-
P015B	A/F SENSOR1 (B1) [Air fuel ratio (A/F) sensor 1 (bank 1) circuit delayed response]	Diagnosis condition	-
		Signal (terminal)	Air fuel ratio sensor 1 signal
		Threshold	The response time of a A/F sensor 1 signal delays more than the specified time computed by ECM
		Diagnosis delay time	-
P014E	A/F SENSOR1 (B2) [Air fuel ratio (A/F) sensor 1 (bank 2) circuit slow response]	Diagnosis condition	-
		Signal (terminal)	Air fuel ratio sensor 1 signal
		Threshold	The response time of a A/F sensor 1 signal delays more than the specified time computed by ECM
		Diagnosis delay time	-
P014F	A/F SENSOR1 (B2) [Air fuel ratio (A/F) sensor 1 (bank 2) circuit slow response]	Diagnosis condition	-
		Signal (terminal)	Air fuel ratio sensor 1 signal
		Threshold	The response time of a A/F sensor 1 signal delays more than the specified time computed by ECM
		Diagnosis delay time	-
P015C	A/F SENSOR (B2) [Air fuel ratio (A/F) sensor 1 (bank 2) circuit delayed response]	Diagnosis condition	-
		Signal (terminal)	Air fuel ratio sensor 1 signal
		Threshold	The response time of a A/F sensor 1 signal delays more than the specified time computed by ECM
		Diagnosis delay time	-
P015D	A/F SENSOR (B2) [Air fuel ratio (A/F) sensor 1 (bank 2) circuit delayed response]	Diagnosis condition	-
		Signal (terminal)	Air fuel ratio sensor 1 signal
		Threshold	The response time of a A/F sensor 1 signal delays more than the specified time computed by ECM
		Diagnosis delay time	-