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Diagnostic Trouble Code: 177
Diagnostic Trouble Code Name: Fuel System too rich Heated Exhaust Gas Oxygen Sensor HO2S(2)
Vehicle Make: Ford
Vehicle Model: Falcon (EF)
Diagnostic Code Entered By: ZerOne
Diagnostic Code Entered On: Wed Oct 06, 2010 11:00 pm
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Please Note: The DTC Information provided has been randomly generated.
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Diagnostic Trouble Code Description:
Fuel System Too Rich
Possible Sensor Faults
ECM
Possible Related Diagnostic Trouble Codes
DTCP0172 or P0175
Circuit / System Description
The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the PCM determines fuel delivery based on sensor signals without oxygen sensor input. During Closed Loop, the PCM adds oxygen sensor inputs and level of purge to calculate short and long term fuel trim adjustments. If the oxygen sensors indicated a lean condition, fuel trim values will be above 0?percent. If the oxygen sensors indicate a rich condition, fuel trim values will be below 0?percent. The values for the short term fuel trim change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1. A block of cells contain information arranged in combinations of engine RPM and engine load for a fuel range of vehicle operating conditions. The long term fuel trim diagnostic is based on an average of cells currently being used. The PCM selects the cells based on the engine speed and engine load. The fuel trim diagnostic will conduct a test to determine if a rich failure actually exists, or if excessive vapor from the evaporative emission (EVAP) canister is causing a rich condition. If the PCM detects an excessively rich condition, DTC?P0172 or P0175 sets.
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