Vehicle
2015 Nissan Qashqai 1.5L Diesel
Title
P0471, Replaced Diesel Particulate Filter Pressure Sensor
Complaint
The customer states the check engine light is on.
Cause
Connected a scan tool and found code P0471 – Exhaust Pressure Sensor “A” Circuit Range/Performance. At idle, used the scan tool to monitor live data and found the diesel particulate filter (DPF) pressure sensor signal parameter was erratic. Using a lab scope, backprobed the DPF pressure sensor signal circuit at the control module and found the signal parameter was erratic, which indicated there was a fault in the sensor or circuitry.
Used a multi-meter to check for the presence of a short or open in the diesel particulate filter pressure sensor wiring harness and found there were no shorts or opens present. Disconnected the DPF pressure sensor connector, visually inspected the connector and terminals, and found no obvious signs of damage. Visually inspected the diesel particulate filter pressure sensor pipe and found no obvious signs of damage. Used the multi-meter to measure the resistance of the DPF sensor and found the measured resistance was not within specifications. The results of these tests verified the diesel particulate filter pressure sensor was faulty.
Correction
Replaced the diesel particulate filter pressure sensor, cleared codes, performed a road test, and verified the vehicle operated properly. The check engine light did not illuminate and no fault codes returned.