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P2178 Buick Code - Fuel Trim System Rich At Cruise Or Acceleration

- Code Popularity: 3,986 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P2178 Buick?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • High fuel pressure
  • Leaking fuel injector or pressure regulator
  • Failed Mass Air Flow (MAF) sensor
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How to Fix the DTC P2178 Buick?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2178 Buick code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

When is the Code Detected?

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

What are Code Possible Symptoms?

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

Code 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 - AutoCodes.com
P2178 Buick Code - Fuel Trim System Rich At Cruise Or Acceleration

Need More Information on the Code?

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