Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Nissan-Datsun >> 2008 >> Maxima SL >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - DTCS P0137 To P0447 >> DTC P0139, P0159 Ho2S2 >> On Board Diagnosis Logic

On Board Diagnosis Logic

The heated oxygen sensor 2 has a much longer switching time between rich and lean than the A/F sensor 1. The oxygen storage capacity of the three way catalyst (manifold) 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 the various driving condition such as fuel-cut.

Fig 1: Heated Oxygen Sensor Voltage Signals Graph
G04875089Courtesy of NISSAN MOTOR CO., U.S.A.
DTC DETECTING CONDITION AND POSSIBLE CAUSE

DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0139
0139
(Bank 1)		 Heated oxygen sensor 2 circuit slow response It takes more time for the sensor to respond between rich and lean than the specified time.
  • Harness or connectors

    (The sensor circuit is open or shorted)

  • Heated oxygen sensor 2
  • Fuel pressure
  • Fuel injector
  • Intake air leaks
P0159
0159
(Bank 2)
scientia non olet · About Mike's Workshop Manuals