What is the P0129 error code? What is the Barometric pressure too low fault? How can I fix P0129 fault? What are the causes and symptoms of the P0129 error code?
What is the P0129 fault code? What does it signify?
The two most important sensors in the engine are the manifold absolute (MAP) and barometric (BARO) sensors. These sensors are typically integrated into one sensor. When the powertrain control module, PCM detects low barometric pressure from either the MAP sensor or BARO sensor, a code P0129 will be set.
The MAP sensor’s primary function is to monitor engine load. It can respond to pressure changes in intake manifold. A loaded engine is more powerful than an idle engine. The voltage signals from your sensor will also change as the motor load changes.
The PCM can monitor atmospheric pressure changes using the BARO sensor. This sensor is similar to the MAP sensor but it is more sensitive for changes in atmospheric pressure. In some vehicles, the two sensors may be combined. The MAP sensor is positioned toward the manifold, and the BARO sensor towards to the atmosphere.
These sensors communicate with the PCM using voltage signals. The BARO sensor has a reference, ground and output voltage circuits. The sensor resistor reacts to changes in atmosphericpressure. The output voltage signal to PCM is affected by this change in resistance. The PCM uses this data to adjust fuel injection and ignition timing. When the voltage signal from the BARO/MAP sensor becomes too low, the fault code P0129 is triggered.
The P0129 fault code can affect vehicles of all makes and models, including Jeep (especially the Grand Cherokee), Dodge Dodge, Hyundai, Mazda Toyota, Chevrolet, and Chrysler.
What causes the P0129 Fault code?
Here are some reasons why P0129 should be set.
- – Sensors for defective MAP and BARO
- Faulty connector or cable problems
- – Open or closed circuit in MAP/BARO sensor wiring
- – Engine vacuum is not maintained due to misfire, engine wear or clogged catalytic.
- – Very dirty and clogged filter
- – Defective PCM
What are the symptoms for the P0129 fault code?
These symptoms may be present if you own a vehicle that has the P0129 code.
- – Illumination for the check engine light
- – Low engine performance
- – Engine hesitation during acceleration
- – Increased fuel consumption
- Engine running in very rich conditions
- – The exhaust emits black smoke
How to Fix the P0129 Fault Code
- To check if the vehicle will return, the codes must first be cleared.
- – Repair of damaged, melted or frayed cables
- – Replace connectors that are worn, loose or have signs of corrosion
- – After the compression test, repair engine vacuum leaks if they exist
- – Replace the polluted filter in your air conditioner
- – Check the resistance to MAP/BARO sensors and replace it if it fails to meet manufacturer specifications
