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.

DTC	CONSULT screen terms (Trouble diagnosis content)	DTC detection condition
P1721	VEHICLE SPEED SIGNAL (Vehicle Speed Signal Circuit)	1	Diagnosis condition	Vehicle speed detected by the output speed sensor is 20 km/h (13 MPH) or more (Only when starts after the ignition switch is turned ON)
			Signal	--
			Threshold	Vehicle speed transmitted from the combination meter to TCM is 5 km/h (3 MPH) or less
			Diagnosis delay time	--
		2	Diagnosis condition	Vehicle speed transmitted from the combination meter to TCM is 36 km/h (23 MPH) or more and the vehicle speed detected by the output speed sensor is 24 km/h (15 MPH) or more
			Signal	--
			Threshold	Vehicle speed detected by the output speed sensor does not decrease despite the 36 km/h (23 MPH) or more of deceleration in vehicle speed received from the combination meter
			Diagnosis delay time	--