Ford P1149 Air/Fuel Ratio Sensor 1 Circuit Range/Performance

Description

Possible causes
– Faulty Air/Fuel Ratio Sensor 1
– Air/Fuel Ratio Sensor 1 harness is open or shorted
– Air/Fuel Ratio Sensor 1 circuit poor electrical connection
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1149 Ford ACURA OBD Code Description

The Air/Fuel Ratio (A/F) sensor 1 is installed in the exhaust system and detects oxygen content in the exhaust gas. The A/F sensor transmits output voltage to the Engine Control Module (ECM)/Powertrain Control Module (PCM). A heater for the sensor element is embedded in the A/F sensor (sensor 1). It is activated and heats the sensor to stabilize and speed the detection of oxygen content by controlling current flowing through the heater. An increase in the current levels off as the applied voltage to the element electrode reaches a certain range because the amount of oxygen which is led through the diffusion layer is limited. The current amperage is proportional to oxygen content in the exhaust gas, so the air/fuel ratio is detected by the measurement of the current amperage. The ECM/PCM compares a set target air/fuel ratio with the detected air/fuel ratio and controls the fuel injection timing.

If the A/F sensor (sensor 1) voltage is low, the air/fuel ratio is lean, and the ECM/PCM uses A/F feedback control to issue a Rich command. If the A/F sensor (sensor 1) voltage is high, the air/fuel ratio is rich, and the ECM/PCM uses A/F feedback control to issue a Lean command.

If the element is not activated or the ECM/PCM terminal voltage is a set value or less for at least a set time period when the power is drawn to the A/F sensor (sensor 1) heater, a malfunction is detected and a DTC is stored.


The OBD2 Code Information Be Applicable For Ford:

2013 Ford Taurus,2013 Ford Mustang,2013 Ford Kuga,2013 Ford Fusion,2012 Ford Focus,2011 Ford Mondeo,2011 Ford Focus,2011 Ford Edge,2010 Ford Mustang,2009 Ford Focus,2008 Ford Fiesta,2008 Ford Escape,2007 Ford Mondeo,2006 Ford Focus,2005 Ford Mustang,2005 Ford Escape,2003 Ford Mustang,2003 Ford Focus,2000 Ford Mustang

 

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