AutoCodes – BMW – P0159 BMW

P0159 BMW Code - O2 Sensor Circuit Slow Response Bank 2 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 2, Rear Heated Oxygen Sensor Bank 2 harness is open or shorted, Rear Heated Oxygen Sensor Bank 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: P0159 BMW indicates O2 Sensor Circuit Slow Response Bank 2 Sensor 2.
Common causes: Common causes include Faulty Rear Heated Oxygen Sensor Bank 2, Rear Heated Oxygen Sensor Bank 2 harness is open or shorted, Rear Heated Oxygen Sensor Bank 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 21,644

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 Jun 14, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0159 BMW 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 P0159 BMW - O2 Sensor Circuit Slow Response Bank 2 Sensor 2 - AutoCodes.com — P0159 BMW Code - O2 Sensor Circuit Slow Response Bank 2 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0159 BMW?

Faulty Rear Heated Oxygen Sensor Bank 2
Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

How to Fix the DTC P0159 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 does this mean?

Code Tech Notes

Replacing the O2 Sensor 2 usually takes care of the problem

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0159 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.

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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 P0159 BMW Code

1. What are the common symptoms of OBDII code P0159 in a BMW?

The common symptoms include poor fuel economy, rough idling, hesitation or jerking during acceleration, and the illumination of the Check Engine Light.

2. What does the OBDII code P0159 indicate in a BMW?

OBDII code P0159 in a BMW indicates a slow response from the downstream oxygen sensor (Bank 2 Sensor 2) in the vehicle's exhaust system.

3. What are the possible causes of OBDII code P0159 in a BMW?

Possible causes of OBDII code P0159 include a faulty oxygen sensor, wiring issues, exhaust leaks, engine misfires, or issues with the engine control module (ECM).

4. How can I diagnose the O2 sensor circuit slow response in Bank 2 Sensor 2 in a BMW?

Diagnosing the issue involves using an OBDII scanner to retrieve the fault code, testing the oxygen sensor's response time, checking the wiring for damage, and inspecting the exhaust system for leaks.

5. Can I still drive my BMW with OBDII code P0159 present?

While it may be possible to drive the vehicle with this code present, it is not recommended as it can lead to reduced fuel efficiency and potential damage to the catalytic converter over time.

6. How can I repair OBDII code P0159 in my BMW?

Repairing OBDII code P0159 typically involves replacing the downstream oxygen sensor (Bank 2 Sensor 2), repairing any damaged wiring, fixing exhaust leaks, and clearing the fault code with an OBDII scanner.

7. Is it necessary to replace the oxygen sensor to fix OBDII code P0159 in a BMW?

In most cases, replacing the oxygen sensor is necessary to resolve OBDII code P0159, as a slow response from the sensor indicates a malfunction that cannot be repaired.

8. Can a dirty or contaminated oxygen sensor cause OBDII code P0159 in a BMW?

Yes, a dirty or contaminated oxygen sensor can cause a slow response and trigger OBDII code P0159. Regular maintenance and cleaning of the sensor may help prevent this issue.

9. How long does it take to repair OBDII code P0159 in a BMW?

The repair time for OBDII code P0159 can vary depending on the extent of the issue and the availability of parts. Typically, the repair can be completed in a few hours by a qualified mechanic.

10. Will resetting the Check Engine Light clear OBDII code P0159 in a BMW?

Resetting the Check Engine Light may temporarily clear the code, but if the underlying issue causing OBDII code P0159 is not addressed, the code is likely to reappear. It is important to diagnose and repair the root cause of the problem.