AutoCodes – MINI – P0140 MINI

P0140 MINI Code - O2 Sensor Circuit Low Voltage Bank 1 Sensor 2

Quick Answer

The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 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: P0140 MINI indicates O2 Sensor Circuit Low Voltage Bank 1 Sensor 2.
Common causes: Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 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 2,495

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 12, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0140 MINI Description

The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

OBDII Code P0140 MINI - O2 Sensor Circuit Low Voltage Bank 1 Sensor 2 - AutoCodes.com — P0140 MINI Code - O2 Sensor Circuit Low Voltage Bank 1 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0140 MINI?

Faulty Rear Heated Oxygen Sensor Bank 1
Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

How to Fix the DTC P0140 MINI?

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.

What does this mean?

Code Tech Notes

Replacing the Rear Heated Oxygen Sensor Bank 1 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0140 MINI 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 P0140 MINI Code

1. What are the common symptoms of OBDII code P0140 in a MINI, indicating an O2 Sensor Circuit Low Voltage Bank 1 Sensor 2 issue?

- Common symptoms include poor fuel economy, rough idling, engine misfires, and an illuminated check engine light.

2. What are the typical causes of OBDII code P0140 in a MINI?

- The main causes are a faulty oxygen sensor, damaged wiring or connectors, exhaust leaks, or a failing catalytic converter.

3. How can I diagnose the O2 Sensor Circuit Low Voltage Bank 1 Sensor 2 issue in my MINI?

- Use an OBDII scanner to retrieve the specific fault code, inspect the oxygen sensor and its wiring for damage, and check for any exhaust system leaks.

4. What are the potential risks of ignoring OBDII code P0140 in my MINI?

- Ignoring this code can lead to decreased fuel efficiency, engine performance issues, and potential damage to the catalytic converter.

5. Can I drive my MINI with OBDII code P0140 while waiting to repair the issue?

- It is not recommended to drive your MINI with this code, as it can cause further damage to the engine and emissions system.

6. How can I fix the O2 Sensor Circuit Low Voltage Bank 1 Sensor 2 problem in my MINI?

- Repair options include replacing the oxygen sensor, repairing damaged wiring or connectors, fixing exhaust leaks, or replacing the catalytic converter if necessary.

7. Are there any DIY tips for troubleshooting OBDII code P0140 in a MINI?

- DIY tips include visually inspecting the oxygen sensor and its connections, checking for exhaust leaks, and using a multimeter to test the sensor's voltage.

8. Is it necessary to reset the OBDII code P0140 after repairing the issue in my MINI?

- Yes, it is recommended to reset the code using an OBDII scanner after fixing the problem to clear the check engine light and monitor the system for any new issues.

9. How much does it typically cost to repair OBDII code P0140 in a MINI at a mechanic or dealership?

- The cost can vary depending on the specific issue, but expect to pay anywhere from $100 to $500 for parts and labor, excluding potential additional repairs.

10. How often should the O2 Sensor Circuit Low Voltage Bank 1 Sensor 2 be replaced in a MINI to prevent recurring issues?

- Oxygen sensors typically last around 100,000 miles, but it's recommended to follow your vehicle's maintenance schedule and replace them as needed to avoid further problems.