BMW DTC P129C – Barometric Pressure Sensor Afterrunning Diagnosis Pressure Implausible
DTC P129C meaning on BMW
DTC P129C on a BMW refers to a fault with the Barometric Pressure Sensor Afterrunning Diagnosis Pressure being implausible. This means that the engine control module (ECM) has detected a discrepancy between the expected and actual barometric pressure readings during the afterrunning diagnosis phase.
BMW DTC P129C symptoms
Symptoms of DTC P129C on a BMW may include poor engine performance, rough idling, reduced fuel efficiency, and in some cases, the vehicle may go into a limp mode where power is limited to protect the engine.
BMW DTC P129C causes
The common causes of DTC P129C on a BMW include a faulty barometric pressure sensor, wiring issues in the sensor circuit, or a problem with the ECM itself. Additionally, a vacuum leak or a malfunctioning intake manifold could also lead to this fault code.
BMW DTC P129C seriousness
While DTC P129C may not cause immediate harm to the vehicle, it can lead to poor engine performance and reduced fuel efficiency. Ignoring this fault code could potentially cause further damage to the engine over time.
How to diagnose DTC P129C on BMW
To diagnose DTC P129C on a BMW, a mechanic would typically use a diagnostic scanner to retrieve the fault code and then perform a visual inspection of the barometric pressure sensor and its wiring. They may also conduct tests to check the sensor’s functionality and compare the barometric pressure readings with a known good source.
How to fix DTC P129C on BMW
Fixing DTC P129C on a BMW usually involves replacing the faulty barometric pressure sensor, repairing any damaged wiring, or addressing any vacuum leaks or intake manifold issues. Once the root cause of the fault is identified and rectified, the fault code should be cleared from the ECM.
How to erase DTC P129C on BMW
To erase DTC P129C on a BMW, the fault code can be cleared using a diagnostic scanner or by disconnecting the vehicle’s battery for a few minutes. However, it is important to ensure that the underlying issue causing the fault code has been resolved before clearing it to prevent it from reoccurring.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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