AutoCodes – BMW – P129C BMW

P129C BMW Code - Ambient Pressure Sensor Run On Pressure Implausible

Quick Answer

The Engine Control Module (ECM) monitors the Ambient Pressure Sensor. Common causes include Faulty Ambient Pressure Sensor, Ambient Pressure Sensor harness is open or shorted, Ambient Pressure 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: P129C BMW indicates Ambient Pressure Sensor Run On Pressure Implausible.
Common causes: Common causes include Faulty Ambient Pressure Sensor, Ambient Pressure Sensor harness is open or shorted, Ambient Pressure 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 2,153

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 Sep 08, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P129C BMW Description

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

OBDII Code P129C BMW - Ambient Pressure Sensor Run On Pressure Implausible - AutoCodes.com — P129C BMW Code - Ambient Pressure Sensor Run On Pressure Implausible

What does this mean?

What are the Possible Causes of the DTC P129C BMW?

Faulty Ambient Pressure Sensor
Ambient Pressure Sensor harness is open or shorted
Ambient Pressure Sensor circuit poor electrical connection

How to Fix the DTC P129C 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 P129C 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 P129C BMW code?

Need more information on how to fix the P129C BMW code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P129C 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 P129C BMW Code

1. What are the common symptoms of OBDII code P129C in a BMW?

- Common symptoms include rough idling, poor engine performance, decreased fuel efficiency, and potential stalling.

2. What could cause the Ambient Pressure Sensor Run On Pressure Implausible error code in a BMW?

- This code is often triggered by a faulty ambient pressure sensor, damaged wiring or connectors, or issues with the engine control module.

3. How can I diagnose the Ambient Pressure Sensor issue in my BMW?

- To diagnose the issue, you can use an OBDII scanner to read the code, visually inspect the sensor and its connections, and perform a pressure sensor test.

4. Can a DIY enthusiast repair the Ambient Pressure Sensor issue in a BMW?

- Yes, if you have experience working on vehicles, you may be able to replace the ambient pressure sensor yourself. However, it is recommended to consult a professional if you are unsure.

5. Are there any simple troubleshooting steps I can take before replacing the Ambient Pressure Sensor?

- Yes, you can start by checking the sensor's wiring for any visible damage, ensuring proper connections, and clearing the error code to see if it reoccurs.

6. How critical is it to address the OBDII code P129C in a BMW promptly?

- It is important to address this code promptly as it can lead to poor engine performance, reduced fuel efficiency, and potential long-term damage if left unresolved.

7. Can a malfunctioning Ambient Pressure Sensor affect other systems in the vehicle?

- Yes, a faulty ambient pressure sensor can impact the engine's air-fuel mixture, leading to issues with the engine's performance and emissions control.

8. Is it necessary to reset the ECU after replacing the Ambient Pressure Sensor in a BMW?

- Yes, resetting the ECU after sensor replacement allows the system to recalibrate and clear any stored error codes related to the previous sensor issue.

9. How much does it typically cost to replace the Ambient Pressure Sensor in a BMW?

- The cost of replacing the ambient pressure sensor can vary depending on the model of your BMW and whether you choose to do it yourself or have a professional mechanic perform the job.

10. Can extreme weather conditions impact the performance of the Ambient Pressure Sensor in a BMW?

- Yes, extreme weather conditions such as high altitudes or drastic temperature changes can affect the ambient pressure sensor's readings and potentially trigger the P129C code.