Have you ever wondered how your car relays information from one module to the next? All this happens without a glitch even when all we do is to steer the car in the intended direction. For your car to be efficient in all its operations, The Manifold Absolute Pressure (MAP) Sensor relays important information to the Power Control Module (PCM) for the engine to load its input. This input involves getting the correct amount of fuel to inject into the cylinders.
A failing MAP Sensor leads to serious implications on fuel control and exhaust pipe emissions. The MAP Sensor can be contaminated with dust and debris, to avoid this scenario, I will take you on a step by step action on how to clean a MAP Sensor.
Regular Screwdriver for unlocking screws holding the MAP Sensor.
CRC Sensor Cleaner: specifically developed to ensure proper cleaning of the MAP Sensor. You can alternatively use any electric parts cleaner that is available from an auto shop.
Wipes or Rags for wiping off dirt or excess cleaning fluid.
The owner’s manual in case you will need to locate the position of the MAP Sensor.
Why Do we Clean MAP Sensors
MAP Sensor should always be well maintained and regularly checked for the accumulation of dust and debris. A faulty MAP Sensor will give wrong readings and transfer this to the Power Control Module (PCM). I thought it is wise to also share the symptoms of a failing or dirty MAP Sensor. This will give us reasons as to why we need to clean our MAP Sensors.
1. Excessive Fuel Consumption
Because a MAP Sensor measures the intake manifold pressure, if it indicates a high engine load to the PCM, it will signal for an increase of fuel to be injected into the engine. This will mean you spend more than you should on fuel. The final result of this is the rapid production of hydrocarbons and carbon monoxide that are released into the environment.
2. Low Engine Power
If the dirty MAP Sensor reads low intake manifold pressure, this will relay a low engine load signal to the PCM. The PCM will reduce the amount of fuel injected in response. In as much, you increase your fuel budget, the amount power you get from your engine will be below normal. The reason behind the loss of power is attributed to the increase in temperature of the combustion chamber.
3. Failed Emission Report
Because of the increase in the level of production of Hydrocarbon, Carbon Monoxide, and CO2, you will always fail on your emission tests not because you are using bad fuel or malfunctioning engine, but because of a dirty MAP Sensor.
4. Rough Running
A faulty map sensor can also cause rough riding. The reason behind this is the big difference in atmospheric pressure and the pressure inside the manifold. You may experience delayed acceleration which may be followed by a sudden surge of power.
5. Vehicle Stalling
A bad or dirty MAP Sensor may force your car to stall immediately you press on the accelerator to start the vehicle. The stalling might be followed by a burning gas smell if the engine had earlier warmed up. This burning smell is as a result of the improper fuel mixture in the combustion chamber. The final result will be an engine Knock.
6. Damaged Spark Plugs
A Faulty MAP Sensor will not properly regulate the flow of air mixing with the fuel in the combustion chamber. When the engine burns too much or too little oxygen as a result of bad sensor information, the spark plugs will suffer damage because they are likely to be covered in residue from poor combustion.
Step By Step Instructions
Step #1: Turn off The Car
Make sure you have turned off the car completely and removed the keys from the ignition. If your car uses an ignition switch, make sure it is in the OFF position.
Step #2: Read Your Car’s, Owner’s Manual
We all are not mechanics, and as such we cannot be able to tell exactly where the MAP Sensor is placed without having to consult the manual. If you confirm with your manual, you will realize that MAP Sensor is located next to the intake/inlet manifold.
If you know the engine part that holds air and fuel mixture, then you will see a MAP Sensor next to it. Check below the wiring harness with several blue, black, and red wire plug coming from it. Unhook the wiring to better access the MAP Sensor.
Step #3: Unplug the Sensor
Follow the sensor cord to the end. You will need to remove the plug from the MAP Sensor. It is best to remove it to avoid any damage to the car or the sensor itself. You squeeze the tab that holds the MAP Sensor in position and quickly release it. Once you have unplugged it, use the screwdriver to unscrew it from its position.
Step #4: Cleaning the Sensor
Get hold of your CRC sensor cleaner or any electrical parts cleaner. Spray the cleaning fluid into the rag (Please do not spray directly to the MAP Sensor). Place the sensor on a level surface and make sure the front face is facing upwards. When cleaning, rub the map sensor carefully in small circular motions. Make sure that all the visible debris and dirt have been removed.
NOTE: Remember not to use water at any stage. The available cleaners are specially made for this cleaning role.
Step #5: Re-mount the MAP Sensor
Now that you have cleaned it, the actual sensor should be visible. Take it back to its mounting position. Do not forget to secure it with the screws and reconnecting the manifold wiring harness.
Step #6: Close the Hood
Now that everything is in place. Make sure you have wiped out any spilled cleaning fluid or dust. Close the hood. Some prefer cleaning the sensors with the batteries disconnected. If you removed the battery connectors, you would have to reconnect them before closing the hood.
Step #7: Test the Vehicle
Restarting your car with a clean MAP Sensor gives the vehicle the opportunity to recognize the clean sensor then the on-board computer can reset itself. This has been known to solve many driveability issues. Testing your car after cleaning the sensor gives you the opportunity to measure its reliability in using the following metrics:
- Fuel consumption
- Emission tests
Although your vehicle will continue to run with a faulty MAP Sensor, the overall engine performance will be compromised and further cause a threat to the environment through carbon emissions. Sometimes your Car’s MAP Sensor is likely to give wrong readings to the PCM if there is a vacuum leakage. It is quite vital that you check the surrounding areas before thinking of replacing the MAP Sensor.
You will notice that MAP Sensor problems are closely related to vehicle injector issues or poor compression in the engine. The MAP Sensor is an important technology that needs an immediate replacement to avoid further damage to your engine.
With this article as your guide and with the right materials, you can now be able to clean up your car’s MAP Sensor all by yourself. This will save you a lot of time and money that you will need if you decide to visit a mechanic. Please comment and share other ideas about how you cleaned your vehicle’s MAP Sensor.