AutoCodes – Cadillac – P2273 Cadillac

P2273 Cadillac Code - HO2S Signal Stuck Rich Bank 2 Sensor 2

Quick Answer

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Common causes include Faulty Heated Oxygen Bank 2 Sensor 2, Heated Oxygen Bank 2 Sensor 2 harness is open or shorted, Heated Oxygen Bank 2 Sensor 2 circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means
P2273 Cadillac indicates HO2S Signal Stuck Rich Bank 2 Sensor 2.
Common causes
Common causes include Faulty Heated Oxygen Bank 2 Sensor 2, Heated Oxygen Bank 2 Sensor 2 harness is open or shorted, Heated Oxygen Bank 2 Sensor 2 circuit poor electrical connection.
Severity
Moderate - service should be scheduled soon.
Can I drive?
The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
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Code Popularity 1,149
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on May 28, 2022
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Code P2273 Cadillac Description

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Engine Control Module (ECM) operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0 - 1, 000 mV. Once sufficient HO2S voltage fluctuation is observed by the ECM, Closed Loop is entered. The ECM uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the ECM to calculate the air-to-fuel ratio sooner.
The Diagnostic Trouble Code (DTC) will be set when the ECM does not detect an HO2S voltage less than 100 mV before accumulated mass airflow exceeds a calibrated value.
OBDII Code P2273 Cadillac - HO2S Signal Stuck Rich Bank 2 Sensor 2 - AutoCodes.com
P2273 Cadillac Code - HO2S Signal Stuck Rich Bank 2 Sensor 2

What are the Possible Causes of the DTC P2273 Cadillac?

  • Faulty Heated Oxygen Bank 2 Sensor 2
  • Heated Oxygen Bank 2 Sensor 2 harness is open or shorted
  • Heated Oxygen Bank 2 Sensor 2 circuit poor electrical connection
  • Low or high fuel system pressure
  • Fuel contamination
  • Faulty fuel injectors
  • Exhaust gas leaks
  • Engine vacuum leaks

How to Fix the DTC P2273 Cadillac?

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

Code Tech Notes

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2273 Cadillac code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P2273 Cadillac Code

1. What are the common symptoms of OBDII code P2273 in a Cadillac?

- Common symptoms include decreased fuel efficiency, poor engine performance, rough idling, and the illumination of the check engine light.

2. What does the OBDII code P2273 "HO2S Signal Stuck Rich Bank 2 Sensor 2" mean for a Cadillac?

- This code indicates that the downstream oxygen sensor on Bank 2 is detecting a consistently rich air-fuel mixture.

3. What are the possible causes of OBDII code P2273 in a Cadillac?

- Possible causes include a faulty oxygen sensor, a vacuum leak, a fuel injector issue, a malfunctioning mass airflow sensor, or exhaust system leaks.

4. How can I diagnose the OBDII code P2273 in my Cadillac?

- Diagnosing this code typically involves checking the oxygen sensor readings, inspecting for any leaks in the exhaust system, and testing the fuel injector operation.

5. Can I drive my Cadillac with the OBDII code P2273 present?

- It is generally not recommended to drive your Cadillac with this code present, as it can lead to further damage and potential safety issues due to poor engine performance.

6. How can I repair OBDII code P2273 in my Cadillac?

- Repair options may include replacing the downstream oxygen sensor on Bank 2, fixing any vacuum leaks, addressing fuel injector issues, or repairing exhaust system leaks.

7. Will resetting the check engine light resolve OBDII code P2273 in a Cadillac?

- Resetting the check engine light may temporarily turn it off, but if the underlying issue causing the code is not addressed, the light is likely to come back on.

8. Is it safe to ignore OBDII code P2273 in a Cadillac?

- Ignoring this code can lead to decreased fuel efficiency, potential damage to the engine, and may cause the vehicle to fail emissions tests.

9. Can a DIY enthusiast fix OBDII code P2273 in a Cadillac?

- Depending on the cause of the code, some DIY enthusiasts may be able to address the issue themselves, such as replacing the oxygen sensor or fixing minor vacuum leaks.

10. How much does it cost to repair OBDII code P2273 in a Cadillac at a professional mechanic?

- The cost of repairing this code can vary depending on the specific issue, but it may range from $200 to $500 or more, including parts and labor.

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