Professional Automotive Advice

If you own a car and have ever had a check engine light turn on, you may have seen a code such as P0108 appear. This code indicates that there is a problem with the Manifold Absolute Pressure/Barometric Pressure Circuit, specifically a high input. In this guide, we will explain the meaning of this code and provide you with step-by-step instructions on how to fix it.

What Does Code P0108 Mean?

The Manifold Absolute Pressure (MAP) sensor measures the pressure inside the intake manifold of your car's engine. The Barometric Pressure (BARO) sensor measures the atmospheric pressure outside of your car. Together, these sensors provide your car's engine control module (ECM) with information about the air pressure in and around your engine. This information is used to determine the correct air/fuel mixture and ignition timing for optimal engine performance.

When the ECM detects that the MAP or BARO sensor is providing a signal that is higher than expected, it will set a P0108 code. This code indicates that there is an issue with the MAP/BARO sensor circuit, which can cause your engine to run poorly, decrease fuel efficiency, and potentially damage your engine if left untreated.

Step-by-Step Guide to Fixing Code P0108

Diagnose the Problem: Before you can fix code P0108, you need to determine what is causing the problem. You can use an OBD-II scanner to read the code and get more information about what is causing it. Check for any other codes that may have been set as well. Once you have diagnosed the problem, you can move on to the next step.

Inspect the MAP/BARO Sensor: The first thing you should do is visually inspect the MAP/BARO sensor and its wiring. Look for any obvious signs of damage, such as frayed wires, corrosion, or physical damage to the sensor. Make sure the sensor is properly connected and securely fastened to its mounting location.

Check the MAP/BARO Sensor Voltage: With the engine running, use a voltmeter to check the voltage output of the MAP/BARO sensor. You should see a reading of around 0.5-1.5 volts at idle. If the voltage reading is higher than expected, you may need to replace the sensor.

Check the MAP/BARO Sensor Ground: Make sure that the ground wire for the MAP/BARO sensor is properly connected and has a good connection. A poor ground can cause the sensor to provide inaccurate readings and trigger code P0108.

Check the Wiring and Connectors: Use a multimeter to check the wiring and connectors for the MAP/BARO sensor. Look for any signs of damage or corrosion, and make sure that all connections are clean and secure.

Test the ECM: If all of the above steps have been completed and the problem still persists, you may need to test the ECM to determine if it is the cause of the problem. This step is best left to a professional mechanic or automotive technician, as it involves specialized equipment and knowledge.

Replace the MAP/BARO Sensor: If you have determined that the MAP/BARO sensor is faulty, you will need to replace it. Make sure to purchase a high-quality OEM or aftermarket replacement sensor that is designed to fit your specific make and model of vehicle.

In conclusion, code P0108 can be a frustrating problem to deal with, but with the right tools and knowledge, you can fix it yourself or seek professional help. By following the steps outlined in this guide, you can ensure that your car is running at its best and avoid any further damage to your engine or fuel efficiency. Remember to always take safety precautions when working on your car, such as disconnecting the battery and using proper tools and equipment. Regular maintenance and inspection of your car's sensors and wiring can also prevent code P0108 from occurring in the first place.