Engine-Codes - Volkswagen - P0151 Volkswagen

P0151 Volkswagen Code - HO2S21 Sensor Circuit Low Voltage

- Code Popularity: 4,967 Views
- Repair Importance Level: 2/3
- Repair Difficulty Level: 2/3
Table of contents
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What are the Possible Causes of the DTC P0151 Volkswagen?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Front Heated Oxygen Sensor Bank 2
  • Front Heated Oxygen Sensor Bank 2 harness is open or shorted
  • Front Heated Oxygen Sensor Bank 2 circuit poor electrical connection
  • Inappropriate fuel pressure
  • Faulty fuel injectors
  • Intake air leaks may be faulty
  • Exhaust gas leaks

Code Tech Notes

Replacing the Front Heated Oxygen Sensor Bank 2 usually takes care of the problem.

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How to Fix the DTC P0151 Volkswagen?

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 connector pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P0151 Volkswagen code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

When is the Code Detected?

The voltage signal from the sensor is lower than the specified time.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • High Fuel Consumption
  • Excessive smoke from Exhaust

What Does the P0151 Volkswagen Code Mean?

The front heated oxygen sensor (or O2 sensor 1) is placed into the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air. The heated oxygen sensor 1 has a closed-end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. The heated oxygen sensor 1 signal is sent to the Engine Control Module (ECM). The ECM adjusts the injection pulse duration to achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical change from 1V to 0V.

P0151 Volkswagen Code - HO2S21 Sensor Circuit Low Voltage

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