AutoCodes – BMW – P126F BMW

P126F BMW Code - Nitrogen Oxide Sensor Trailing Throttle Check Linear Lambda Signal Too Rich

Quick Answer

The Engine Control Module (ECM) monitors the Nitrogen Oxide (NOx) Sensor. Common causes include Faulty Nitrogen Oxide (NOx) Sensor, Nitrogen Oxide (NOx) Sensor harness is open or shorted, Nitrogen Oxide (NOx) Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P126F BMW indicates Nitrogen Oxide Sensor Trailing Throttle Check Linear Lambda Signal Too Rich.
Common causes: Common causes include Faulty Nitrogen Oxide (NOx) Sensor, Nitrogen Oxide (NOx) Sensor harness is open or shorted, Nitrogen Oxide (NOx) Sensor circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,088

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 02, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P126F BMW Description

The Engine Control Module (ECM) monitors the Nitrogen Oxide (NOx) Sensor. The ECM sets the OBDII code when the Nitrogen Oxide (NOx) Sensor is not to factory specifications.

OBDII Code P126F BMW - Nitrogen Oxide Sensor Trailing Throttle Check Linear Lambda Signal Too Rich - AutoCodes.com — P126F BMW Code - Nitrogen Oxide Sensor Trailing Throttle Check Linear Lambda Signal Too Rich

What does this mean?

What are the Possible Causes of the DTC P126F BMW?

Faulty Nitrogen Oxide (NOx) Sensor
Nitrogen Oxide (NOx) Sensor harness is open or shorted
Nitrogen Oxide (NOx) Sensor circuit poor electrical connection

How to Fix the DTC P126F BMW?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P126F BMW 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.

Need more information about the P126F BMW code?

Need more information on how to fix the P126F BMW code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P126F BMW code diagnosed by a professional: Find a repair shop in your area

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 P126F BMW Code

1. What are the common symptoms of OBDII code P126F in a BMW related to the Nitrogen Oxide Sensor Trailing Throttle Check Linear Lambda Signal Too Rich?

- Common symptoms include decreased fuel efficiency, rough idling, and potentially a noticeable decrease in engine performance.

2. What are the possible causes of OBDII code P126F in a BMW?

- Possible causes include a faulty nitrogen oxide sensor, issues with the exhaust system, a malfunctioning lambda sensor, or problems with the engine's air-fuel mixture.

3. How can I diagnose the OBDII code P126F in a BMW?

- Diagnosing this code usually involves using a diagnostic scanner to read the error code, checking the nitrogen oxide sensor's connections, inspecting the exhaust system for leaks, and testing the lambda sensor's functionality.

4. What are some repair tips for fixing OBDII code P126F in a BMW?

- Repair tips may include replacing the faulty nitrogen oxide sensor, repairing any leaks in the exhaust system, recalibrating the lambda sensor, and ensuring the air-fuel mixture is within the correct parameters.

5. Can driving with OBDII code P126F in a BMW cause further damage to the vehicle?

- Continuing to drive with this code present may lead to decreased engine efficiency, potential damage to the catalytic converter, and increased emissions.

6. How much does it typically cost to repair OBDII code P126F in a BMW?

- The cost of repairing this code can vary depending on the exact cause of the issue, but it may range from a few hundred to a few thousand dollars, including parts and labor.

7. Is it safe to continue driving my BMW with the OBDII code P126F present?

- It is generally not recommended to drive with this code present, as it can lead to decreased performance and potential damage to the vehicle's emissions system.

8. Can I reset the OBDII code P126F in my BMW without repairing the issue?

- While you can clear the error code using a diagnostic scanner, it is important to address the underlying issue causing the code to prevent further problems.

9. How long does it typically take to repair OBDII code P126F in a BMW?

- The repair time can vary depending on the exact cause of the code and the availability of parts, but it may take a few hours to a full day to complete the necessary repairs.

10. Are there any preventative measures I can take to avoid OBDII code P126F in my BMW?

- Regular maintenance, such as ensuring timely sensor inspections and addressing any engine performance issues promptly, can help prevent the occurrence of this code.