AutoCodes – Volkswagen – P0140 Volkswagen

P0140 Volkswagen Code - HO2S12 Sensor Circuit No Activity Detected

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 Volkswagen indicates HO2S12 Sensor Circuit No Activity Detected.
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 35,084

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 Volkswagen 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 Volkswagen - HO2S12 Sensor Circuit No Activity Detected - AutoCodes.com — P0140 Volkswagen Code - HO2S12 Sensor Circuit No Activity Detected

What does this mean?

What are the Possible Causes of the DTC P0140 Volkswagen?

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 Volkswagen?

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 Volkswagen 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 Volkswagen Code

1. What are common symptoms of OBDII code P0140 in a Volkswagen?

- Common symptoms include poor fuel economy, rough idling, engine misfires, and the illumination of the check engine light.

2. What does the OBDII code P0140 for a Volkswagen indicate?

- The code P0140 indicates that the HO2S12 sensor circuit has detected no activity, signaling a potential issue with the oxygen sensor in bank 1 sensor 2.

3. What are some possible causes of the HO2S12 sensor circuit no activity detected in a Volkswagen?

- Possible causes include a faulty oxygen sensor, damaged wiring or connectors, exhaust leaks, or an issue with the engine's fuel system.

4. How can I diagnose the cause of OBDII code P0140 in my Volkswagen?

- To diagnose the issue, you can use an OBDII scanner to read the code and inspect the oxygen sensor, wiring connections, and exhaust system for any visible damage or issues.

5. Can a faulty oxygen sensor cause other problems in my Volkswagen besides triggering the P0140 code?

- Yes, a faulty oxygen sensor can lead to decreased fuel efficiency, increased emissions, and potential damage to other engine components over time.

6. Is it safe to continue driving my Volkswagen with the P0140 code present?

- It is not recommended to drive the vehicle with the P0140 code active, as it can lead to decreased performance and potential long-term damage to the engine.

7. How can I repair the HO2S12 sensor circuit no activity detected issue in my Volkswagen?

- Repair options include replacing the oxygen sensor, repairing damaged wiring or connectors, fixing any exhaust leaks, and resetting the check engine light with an OBDII scanner.

8. Can I reset the P0140 code in my Volkswagen without fixing the underlying issue?

- While you can reset the code using an OBDII scanner, it is important to address the root cause of the problem to prevent the code from reoccurring.

9. How much does it typically cost to repair the HO2S12 sensor circuit no activity detected in a Volkswagen?

- The cost of repair can vary depending on the specific issue, but it may range from $100 to $300 for parts and labor, excluding any additional diagnostic fees.

10. How often should I have the oxygen sensors in my Volkswagen inspected or replaced to prevent OBDII code P0140 from occurring?

- It is recommended to have the oxygen sensors inspected during routine maintenance intervals, typically every 30,000 to 60,000 miles, and replace them as needed to prevent issues like code P0140.