OBDII Code List

P2178 BUICK - Fuel Trim System Rich At Cruise Or Acceleration

Repair Importance Level: 3/3
Repair Difficulty Level: 2/3   
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P2178 BUICK Possible Causes

  • High fuel pressure
  • Leaking fuel injector or pressure regulator
  • Failed Mass Air Flow (MAF) sensor

First diagnose P2178 BUICK code

    Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded terminals.

Cost of diagnosing the P2178 BUICK code

    Labor: 1.0

    The cost of diagnosing the P2178 BUICK code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle's make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

When is the P2178 BUICK code detected?

The Engine Control Module (ECM) has detected a rich air/fuel ratio

P2178 BUICK Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P2178 Buick Description

The Engine Control Module (ECM) 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 Loop and Closed Loop. During Open Loop, the ECM determines fuel delivery based on sensor signals without heated oxygen sensor (HO2S) input. During Closed Loop, the ECM adds HO2S inputs to calculate the short and long term fuel trim (FT) adjustments. If the HO2S indicates a lean condition, the fuel trim values will be above 0 percent. If the HO2S indicates a rich condition, the FT values will be below 0 percent. The short term FT values change rapidly in response to the HO2S voltage signals. The long term FT makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1.
OBDII Code P2178 Buick - Fuel Trim System Rich At Cruise Or Acceleration -

P2178 BUICK More Information

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