Symptoms Your Mass Air Flow Sensor Is Bad
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All modern vehicles make use of sophisticated software and processors, just like your home computer, to run your vehicle, whether it's the engine, transmission, or any safety and driver assistance features.
The ECU (electronic control unit) in your Cadillac relies on data collected from various sensors located in the engine's various components to run the engine. The ECU constantly monitors this data and adjusts ignition timing and fuel supply to allow the engine to perform.
Our article takes a look at MAF sensor symptoms. Read on as we share some technical information on this important sensor in your engine bay.
What Is a Mass Air Flow Sensor?
The Mass Air Flow sensor, or MAF, is tasked with measuring the volume of air entering the intake system of the engine and is usually found in the intake piping of your engine just after the air filter.
This airflow data is sent to the ECU, which then uses this information to determine the amount of fuel that needs to be supplied through the fuel injection system according to the volume of air.
All internal combustion engines, both gasoline and diesel, require specified air-to-fuel ratios to perform optimally. Without the correct information from your Cadillac's MAF, the ECU will not be able to control this air-to-fuel ratio.
Common Symptoms of a Bad Mass Air Flow Sensor
Your Cadillac will display some easy-to-spot MAF sensor symptoms.
1. Check Engine Light Illuminates
The Check Engine Light, or CEL, is found in the instrument gauge cluster of your Caddy.
The light is typically an engine-shaped symbol that lights up in orange when the ECU detects a problem within the vehicle's various electronic systems. Data from a faulty MAF will most certainly cause the ECU to alert the driver to a problem by illuminating the CEL.
2. Poor Fuel Efficiency
As we have learned, the MAF sensor sends important air volume information to the ECU to calculate the fuel requirements. The ECU's default output when not able to determine the correct fuel volumes is to oversupply fuel, causing the engine to run "rich" with more fuel than is necessary, which results in poor fuel efficiency.
This default "rich" setting of the ECU is in place as it is safer for the engine than running "lean" with too little fuel, which causes burnt valves and further problems.
3. Engine Performance Issues
Incorrect air-to-fuel ratios will cause the engine to run poorly and not deliver its full power. Acceleration will be slowed, and steep hills will become difficult for your Cadillac to tackle.
4. Rough Idling
Along with poor engine performance, a faulty MAF will cause the engine to run rough, and when idling, the engine's operation will not be as smooth as it should. The chances of stalling are always higher.
5. Black Exhaust Smoke
The "rich" running settings, as mentioned, will cause too much fuel to be supplied, and this will result in excessive black smoke from the exhaust as fuel is not correctly combusted.
6. Unusual Engine Surging or Jerking
Not just poor power and performance will be noticed, but your Cadillac may end up running erratically with surges or jerking as the engine struggles with inconsistent air/fuel supply from the ECU.
7. Reduced Power Output
The ECU and its programmed settings are designed to allow your Cadillac to deliver optimal power output. Simply put, a bad MAF will result in reduced power.
Causes of Mass Air Flow Sensor Failure
Unfortunately, just like all electronic devices such as smartphones, computers, or even your digital watch, things can go wrong.
Contamination or Dirt Build-Up
Over time, tiny dirt particles may escape the filter medium of an air filter and start to build up on the delicate MAF sensor element. If we consider the sheer volume of air an engine sucks in over many years and miles of driving, there's bound to be some dirt build-up that will cause issues.
Electrical or Wiring Issues
A loose connector on the MAF sensor will cause interrupted electronic signals to the ECU, or a frayed wire from the wiring loom rubbing in the engine bay will also cause incorrect readings.
The connectors on the MAF's small PC board may also be damaged or loose.
Age and Wear Over Time
With the huge volumes of air being sucked through the MAF, eventually, some wear and degradation of the delicate sensor element or PC board will happen.
How to Diagnose a Bad MAF Sensor
Owners armed with some mechanical knowledge and the correct equipment should be able to diagnose MAF sensor symptoms.
Using an OBD-II Scanner
The quickest and most reliable diagnosis is made with an OBD-II scanner tool that plugs into your Caddy's ECU via the OBD port. The scanner uploads all the recorded or live data and reads any error codes to identify any issues, such as the bad MAF.
Visual Inspection Tips
A visual inspection, if you know what to look for, will help identify any obvious issues, such as dirt build-up or a loose electrical connection.
Professional Diagnostic Recommendations
Not all of us have the necessary tools, such as an OBD-II scanner to plug in and run diagnostics, nor the mechanical insights to really fix our vehicles. Booking your Caddy into any one of Cadillac's certified service centers is the recommended route to take to identify MAF sensor symptoms.
Cadillac-certified technicians have the necessary training and authentic expertise that is required to efficiently and correctly repair and maintain your iconic Cadillac.
Get Your Cadillac Serviced at Colonial Cadillac
The last thing you need is to have your luxury Cadillac repaired by a workshop that is not all that familiar with your Cadillac service requirements, risking your vehicle's proper running.
Rather, give your automotive investment the best possible care that comes from a certified Cadillac service center.
Colonial Cadillac in New London, CT, offers an unmatched and dedicated service experience.
With our team of Cadillac-certified and expert technicians fully knowledgeable on all Cadillac models, you know that your vehicle will be getting the best care while we address its MAF sensor symptoms.
