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DTC P1278, P1288 A/F SENSOR 1 EC-531 C D E F G H I J K L M A EC
2005 Pathfinder DTC P1278, P1288 A/F SENSOR 1 PFP:22693 Component Description UBS00KF2 The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen- = 1, but also in the lean and rich range. Together with its control electronics, the sensor range (0.7 < < air). The exhaust gas components diffuse through the diffusion gap at the An electronic circuit controls the pump current through the oxygen- = 1. Therefore, the air fuel ratio (A/F) sen- sor 1 is able to indicate air/fuel ratio by this pumping of current. In ° C (1,292 - 1,472 ° F). CONSULT-II Reference Value in Data Monitor Mode UBS00KF3 Specification data are reference values. On Board Diagnosis Logic UBS00KF4 To judge the malfunction of air fuel ratio (A/F) sensor 1, this diagnosis measures response time of the A/F sig- SEF579Z SEF580Z MONITOR ITEM CONDITION SPECIFICATION A/F SEN1 (B1) ● Engine: After warming up Maintaining engine speed at Fluctuates around 1.5V DTC No. Trouble diagnosis name DTC detecting condition Possible Cause P1278 Air fuel ratio (A/F) sensor 1 ● The response (from RICH to LEAN) of the A/F ● Harness or connectors ● Air fuel ratio (A/F) sensor 1 ● Air fuel ratio (A/F) sensor 1 heater ● Fuel pressure ● Fuel injector ● Intake air leaks ● Exhaust gas leaks ● PCV ● Mass air flow sensor P1288 |