Top Mass Airflow / Vane Airflow Questions
What function does the MAF/VANE AIRFLOW sensor perform?
The MAF sensor informs the engine control computer of the load on the engine by measuring airflow in grams per second of air over a sensing element or in the case of the VANE AIRFLOW sensor, the position of the door is measured as it is moved by the air entering the unit. This information is used by the ECM to calculate fuel delivery.
How can a malfunctioning MAF/VANE AIRFLOW sensor affect my vehicles’ operation?
A malfunctioning MAF/VANE AIRFLOW sensor can cause any one or more of the following symptoms: hesitation, stalling, poor fuel economy or poor engine performance.
How can I determine if the MAF/VANE AIRFLOW sensor is bad?
Visually inspect the sensor element in the MAF for damage or for a burnt smell. In the VANE AIRFLOW sensor, inspect the door for binding or for a burnt smell. unit. Start the engine and tap lightly on the unit. If tapping causes an engine malfunction or intermittent operation the unit is faulty and must be replaced.
What should I do before I replace the MAF/AIRFLOW sensor?
First check for and note any MAF/VANE AIRFLOW related trouble codes stored in the engine control computer. Inspect the wiring harness and connectors for damage. All MAF/VANE AIRFLOW relays MUST be checked for resistance (20 OHMS resistance or greater). Anything relay under this resistance must be replaced. Failure to do this will damage the replacement unit. Moisture entering the unit through split air ducts, or gas/oil fumes from the engine can also cause premature failure. Repair or replace as necessary. Correct any pre-existing conditions that caused stored trouble codes.
What goes bad in VANE AIRFLOW type units?
The most common causes are: worn vane assembly, cracked housing, or cracked printed circuit board. These conditions require unit replacement.
What goes bad in MAF sensors?
The most common causes are: cracked circuit boards, burned sensing filaments, poor solder joints, defective conformalcoat, or loose printed circuit board components.
What are the most common causes of MAF/VANE AIRFLOW sensor problems?
Over-voltage sources from relays, shorted wiring, cracked printed circuit boards, moisture entering the unit through split air ducts, electrical connections and wiring, air intake obstructions or gas/oil fumes from the engine can cause failure. Check air filter and air ways for dirt or debris. Check for loose or faulty connectors, broken or faulty wiring. Be sure to check these to prevent damage to the replacement unit.