Switches and Sensors
MAF Sensors: Common Issues and Causes for Misdiagnosis
MAF sensors essentially measure the amount of air that flows into the engine to help create an optimal air-to-fuel ratio that allows the vehicle to perform at its full potential and efficiently.
Also known as air mass sensors, it continues on being a critical component to modern vehicles as emissions and fuel efficiency, stay at top priority for vehicle manufacturers. With such exacting tolerances, challenges are likely to follow.
CONDITIONS FOR PRECISION
The precision that the MAF sensor is expected to deliver at makes it a powerful but delicate device; it can be easily contaminated by dirt, debris and oil. Contamination can occur as early as 18,000 to 25,000 miles, depending on the model of the vehicle. Sensors for turbo-diesel engines in particular are subjected to high stresses since airflow and speeds are very high.
A defective or clogged MAF sensor can supply incorrect input signals to the engine control unit (ECU) which, as a result, controls other components incorrectly.
A CLUE TO MORE ISSUES
A faulty MAF sensor is often indicative of a problem somewhere else in the system. After all, it is highly unlikely for a sensor to clog on its own. Clogged sensors are often indicative that there are leaks in the air intake system. Dirt particles can enter with the intake of air and damage the sensitive sensor element. Excessive oil mist from the crankcase ventilation, water ingress and exposure to road salt can further exacerbate the issue.
If an ECU is reporting a MAF fault code, it does not necessarily mean that the unit is at fault. Unmetered air entering the engine from a split intake hose, crank case ventilation breather pipe or even a sticking EGR valve can trigger a MAF fault code.
It is important to be mindful that the engine breather and vacuum hoses are in good condition and securely located before and after replacement of the MAF sensor. Leaks in any of these hoses can lead to misdiagnosis.
When replacing a MAF sensor, it is good practice to replace the air filter at the same time. By doing this, installers reduce the chance of premature failure and time-consuming warranty claims.
CAMBIARE QUALITY ASSURANCE AND SUPPORT
With product quality at the centre of Cambiare’s priority, all Cambiare MAF sensors are tested in-house, prior to dispatch. Only units that meet Cambiare’s strict performance criteria receive a ‘QC PASSED’ stamp as a sign of approval.
To further support customers with their technical enquiries, Cambiare has a dedicated technical specialist team that can be reached via the tech hotline, 0845 543 8280.