If in a testing of the sensor an individual discovers that the sensor is in good condition and its functioning is not causing a specific driveability problem, the wiring harness and the connectors situated between the sensor and the PCM should also be checked for open or short circuits. If no problems are identified, take the car to a dealer service department or an authorized auto repair shop. The Mass Airflow (MAF) sensor is fitted in the air intake duct Take for instance, the hot-wire sensing elements that is used to determine the molecular mass of air inflow into the engine. As air is over the hot wire it cools and this change in temperature is converted into an analog voltage signal to the PCM the PCM in turn calculates pulse width of the fuel injector needed for right air to fuel mixture. There are numerous problems that are associated with a bad MAF sensor ranging from surging, stalling, rough idle and other driveability complaints and the Electronic Engine Control system is known to be able to sense different problems with the MAF sensor and set a range of trouble codes. To verify power to the MAF sensor remove the connector of the sensor and place the positive probe of the voltmeter to the B+ terminal of the harness connector then the negative probe to the connector GND terminal, while the ignition should be on without turning the engine on the voltmeter, should read over 10 volts. When reconnecting the electrical connector, backprobe the MAF SIG and GND terminal with the voltmeter while starting the engine, expecting to see the reading to be between 1.0 and 1.7 volts at idle as the RPM increases the reading should go to between 1.7 and 3.0 volts. The customers should turn off the engine, unplug the MAF harness connector, and by using an ohmmeter, touch one probe to the MAF SIG terminal and the other probe to the GND terminal; if the circuit is open, it means that the hot-wire element is damaged. If voltage is correct, look at the wiring harness for opens or damaged part of it. If drivability issues remain and all test results are normal, the sensor should be taken to a professional workshop as voltage signal abnormalities cannot be detected with a voltmeter. For replacement, the plastic MAF sensor body and the metal air duct must be replaced simultaneously, since the two are bend together and it is not possible to replace them individually. Unplug the electrical connector of the MAF sensor, unbolt the clamp that anchors the sensor to the intake air duct, and then remove the four nuts connecting the sensor to the air cleaner housing before installing a new one with its electrical connector.
