This means the engine's computer (PCM) is receiving a signal from the MAF sensor that indicates the airflow is lower than it actually is. Several things can cause this:
* Faulty MAF sensor: This is the most common culprit. The sensor itself might be dirty, damaged, or simply failing.
* Dirty air filter: A severely clogged air filter restricts airflow, leading to a low reading from the MAF sensor.
* Vacuum leaks: Leaks after the MAF sensor can also cause a low airflow reading. Air entering the system undetected will skew the MAF sensor's measurement.
* Wiring problems: Damaged or corroded wiring between the MAF sensor and the PCM can interfere with the signal.
* Damaged intake system: A problem with the intake tubing (e.g., a crack or hole) can also cause inaccurate readings.
What to do if you get this code:
1. Check the air filter: This is the easiest and cheapest thing to check first. Replace it if it's dirty.
2. Inspect the MAF sensor: Look for visible damage, dirt, or debris on the sensor element (the hot wire inside). Do not touch the sensor element with your bare fingers; the oils from your skin can damage it. Clean it carefully with MAF sensor cleaner (available at auto parts stores) if it's dirty, following the cleaner's instructions precisely.
3. Check for vacuum leaks: Visually inspect all vacuum hoses and connections for cracks or leaks.
4. Inspect wiring: Examine the wiring harness connecting the MAF sensor to the PCM for any damage or corrosion.
5. Have the MAF sensor tested: A mechanic can test the MAF sensor to determine if it's functioning correctly. Sometimes replacing the sensor is necessary.
If you're not comfortable performing these checks yourself, it's best to take your Tahoe to a qualified mechanic for diagnosis and repair. Ignoring the problem can lead to poor engine performance, reduced fuel economy, and potential damage to the engine.
