They compare the readings to the specifications or. False air 439 mass airflow maf sensor 436 speed density 435 tap test 438 vane. The breakdown shown here is of the mass air flow sensor housing and shows the individual parts that make up the full unit. For this check, all electrical accessories should be switched off coolant fan must not run during test.
The temperature sensor measures ambient air temperature to adjust for differences in climate and humidity and helps regulate the temperature of the wire. Remove the mass air flow sensor from the air intake bellow. How to test a mass air flow maf sensor without a wiring. As the intake air increases, the voltage from the maf sensor increases. Chec the output of the maf sensor while doing a full throttle run in 2nd gear, as shown in figure b. This is necessary to determine how much fuel to inject, when to ignite the cylinder, and when to. Of course, waveform captures from your scope are often all that are needed to confirm a faulty maf sensor. If you test the other leads associated with the maf and you see another 5v reference and a return voltage those will be for the intake air temp. Air changes its density with temperature and pressure. The most common way to test the 5 wire vw mass air flow maf sensor is just to unplug it with the engine running.
They compare the readings to the specifications or to the readings of a knowngood mass airflow sensor. Replacing a mass air flow sensor is fairly straight forward, so most of the cost comes from the cost of the part, and not the labor. In addition to testing and calibration, another important factor for performance is the use of highquality rtd sensors. Turbo pressure reached 2000mbar, so turbo seems to be fine. It is for use with all psi vortec 58x engine harnesses. Symptoms of a bad mass air flow sensor include decreased fuel economy, starting trouble, stalling shortly after starting, rough idling, and jerking during acceleration. Here is a fast and accurate way to track a mafs performance and output to the. Zssc3154 application note mass air flow maf sensor. C bus interface offer mass flow measurement for air and gases based on a highly sensitive thermal measuring principle. On most current vwaudi engines, the actual maf value can be found in group 002, field 4 or group 003, field 2. Mazda miata 1992, black mass air flow adapter by weaponr. May 04 2020 2010acurardx mass air flow sensor manual 15 pdf drive search and download pdf files for free. Its always a good idea to test a mass airflow maf sensor before replacing it.
In automotive applications, air density varies with the ambient. Mass airflow sensors maf have the responsibility of reporting the amount of air entering the engine to the powertrain control module pcm. The wbi series includes unidirectional as well as bidirectional flow ranges. In our shop, weve found that a snapthrottle maf test for ford products should always produce a peak voltage of at least 3. Check the connection cables between the removed control unit connector and sensor connector for transmission circuit diagram for pin assignment necessary. Heat filmmass sensor earlier models flow rectifier temperature sensor heat film sensor electronic unit. Made from rugged plastic, it bolts to flat inlet of the sensor. The calibration gas for each specific flow sensor or flow meter is detailed on the product label. The trucks computer uses this signal to determine engine load and adjusts ignition timing and fuel timing for optimum engine performance. Part 1 the basics of testing a mass air flow maf sensor. Its rare for the mass air flow maf sensor to go bad and not leave a diagnostic trouble code but sometimes. Shouldnt the mass air flow sensor dictate the voltage going out to the ecm. The total mass flow of the egrair mixture passing through intake manifold 16 is calculated for combinations of engine speed and engine load over the effective speedload range for the strategy.
Pdf the experiment work to know locations of mass air flow sensor maf and intake air temperatureiat sensors, and classify its types. The air mass meter figures out the air flow and modifies your car or trucks air and fuel mixture. As gas flows across the sense element, heat is transferred from upstream to downstream. Mass air flow intro spanish download pdf 1 mb mass air flow intro.
Pdf mass air flow and temperature sensors testing by scan. It consists of a tubular housing with flow straightener, sensor protection, and sensor module. Vehicles prior to 1996 could have maf without an iat. The maf or mass air flow sensor has become a standard part on most. Mass air flow maf sensors the mass air flow sensors converts the amount of air drawn into the engine into a voltage signal. How to troubleshoot a mass airflow sensor axleaddict. This means that more energy is used with larger air mass. Explain in detail the testing procedure of a maf sensor.
Inside the sensor, theres a sense element with a heated surface. If the specified value is obtained but dtc memory has a dtc concerning mass air flow maf sensor, check the voltage supply of the mass air flow maf sensor. When one reads about mass air flow sensor contamination, it is important to recognize that a modern engine can use one of five distinct categories of air measuring devices, each of which works on very different physics principles. Testing air mass meters checking an air mass meter on the vehicle potentially faulty air mass meters can be checked whilst still fitted to the vehicle. Mass air flow maf sensors standard mass flow sensor. The snapthrottle test is performed the same way as for ignition analysis.
In modern cars, the only way to test the mass air flow sensor is with a scan tool. The primary components of the maf sensor are a thermistor, a platinum hot wire, and an. A mass air flow sensor maf is a sensor used to determine the mass flow rate of air entering a fuelinjected internal combustion engine the air mass information is necessary for the engine control unit ecu to balance and deliver the correct fuel mass to the engine. At the simplest level, an airflow sensor, or more precisely a mass air flow sensor, is a device with two pressure ports where gas flows from one port to the other see figure 1. Order mass air flow sensormeter for your vehicle and pick it up in storemake your purchase, find a store near you, and get directions. Mechanics measure the amount of air flow mass air flow sensor readings at different rpms. As can be seen clearly, the specified air flow is much higher than the actual measured air flow. As stated before, the mass air flow test is a very easy and simple test but there are a couple of things that have to be done first. For an air mass meter to work, it is associated precisely to your trucks onboard cpu and is thus able to keep track of the amount oxygen in the motor, and then regulates the air accurately to assure proper car functioning. This will be easy to spot because the return voltage will be less than 5v or better be. Maf sensors troubleshooting and fault diagnosis advice. Common signs of problems with a mass airflow sensor include running rich at idle or lean under load, decrease in fuel efficiency, and rough idles.
Save time, money, and labor by replacing only the maf sensor instead of the entire mass air flow assembly. Assuming this test is done at or near sealevel, the peak output of the sensor in. The manual version of the automotive mass air flow sensor mafs test stand is an air flow measurement test stand designed for setting and measuring the mass flow rate of through mass air flow sensors and other induction components. Air flow and mass sensing devices air flow and mass sensing devices. Air flow meter to maf conversion the replacement of a stock vanestyle air flow meter afm with a mass air flow maf sensor is one of the most effective ways to improve performance on a naturally aspirated engine. But the real key to testing with a multimeter is the signal return lead. It is mounted in the intake pipe between the air filter housing and the intake manifold. The lpe maf solves the mass air flow signal drop out problem found on 20052006 c6 corvettes that occurs under. It may not possible to conduct the same extensive testing that amms undergo in a dedicated test facility such as lucas but faulty sensors can still be diagnosed in the garage environment without. The electrically heated sensor element rises into the air. Jan 23, 2012 testing a mass air flow sensor for a volvo xc v70. The symptoms of a bad mass air flow sensor include low engine power, poor fuel economy, an engine that wont start, a check engine light on the dash and a gas smell from the exhaust fumes. Have your vehicle checked if the check engine light illuminates.
This is necessary to determine how much fuel to inject, when to ignite the cylinder, and when to shift the transmission. While plugged in, there is erratic nondetectable voltage, onoff, onoff. Maf sensor testing the techassist team its always a good idea to test a mass airflow maf sensor before replacing it. Conduct an electronic test of the mass air flow sensor by the engine management control unit. I also show you how you can figure out the wires without a wiring diagram. Results for mass air flow sensor select a vehicle for exact fit parts select new vehicle select new vehicle. This universal adapter will let you attach that air cleaner of your choice to the inlet of your airflow sensor. Mass air flow sensor breakdown the mass air flow sensor is a unit that sits at the front of the air intake measuring the oxygen content of the air entering the motor. Mass airflow sensors measuring low differential pressures altitude and gas density correction. I also show you how you can figure out the wires without a. P1101 maf mass air flow sensor out of self test range p1102 maf mass air flow sensor in range but lower than expected p1103 maf mass air flow sensor in range but higher than expected p1104 maf mass air flow ground malfunction. Nov 03, 2015 the total mass flow of the egrair mixture passing through intake manifold 16 is calculated for combinations of engine speed and engine load over the effective speedload range for the strategy.
If your check engine light is on and your car has any of these symptoms, you can check the maf sensor with an obdii code reader. If the maf is bad either because its not producing a signal or producing an erratic one, the cars idle will return to normal and the car will seem to run fine. In order to keep a car running at its best, it is important to make sure that the engine is in good condition. The airmass sensor is used to measure the intake air mass. Mass airflow sensors maf have the responsibility of reporting the amount of air entering the engine to the. Mar 22, 2010 the most common way to test the 5 wire vw mass air flow maf sensor is just to unplug it with the engine running. Average rating from 5,040 customers who received a check engine light is on inspection. How to test the mass air flow sensor in a nissan truck. This maf sensor is recommended for supercharged, turbocharged and other high output engine applications. Ena mass air flow sensor maf compatible with 19962002 chevrolet gmc 4. Mass air flow sensor, mass air flow sensor replacement. The mass air flow sensors converts the amount of air drawn into the engine into a voltage. The test probe and chip satisfy more stricter measurement category than the meter.
You must follow vehicle service manual cautions when working around the air bag components or wiring. Measuring output voltage by backprobing the plug wires. The pcm tune must match the characteristics of this maf sensor. Pdf experimental stand to evaluate engine mass air flow maf. A bad mass air flow sensor is often the likely culprit if your car isnt running as it should. How to test the mass air flow sensor in a nissan truck it. A sensor is calibrated for one gas but may be used with other gases by applying a correction factor to the output. Help, advice and diy tutorials on volvos extremely popular car line volvos 1990s bread and butter cars powered by the ubiquitous and durable volvo inline 5cylinder engine. This is the same mass air flow sensor used in the lpe 600 hp and 725 hp 2005 2009 c6 corvette twin turbocharged engine packages. One of the key components to make this happen is the mass air flow sensor or maf. Be sure that the air flow direction arrows, located. The ecm needs to know intake air volume to calculate engine load. Here is a fast and accurate way to track a mafs performance and output to the pcm.
Heat is extracted from the sensor element by the air. Part 1 vw mass air flow maf sensor test 5 wire type. If you are going to replace the maf yourself, then id always recommend buying an oem mass air flow sensor. Pdf in this paper an experimental setup was designed and realized in laboratory to test and measure the engine mass air flow sensor used in. The mass air flow maf sensor in a nissan truck sends a signal to the trucks computer. Mass air flow sensor best maf sensor for cars, trucks. The output of the thermal mass flow sensor is directly related to the specific heat characteristic of the gas being measured. Faulty bosch mass air flow sensor the graph below was measured on a 81kw tdi engine afn, after 180,000 km under wot wide open throttle.
Slp 23060 mass air flow sensor installation instructions. The air mass sensor is used to measure the intake air mass. The zssc3154 sensor signal conditioner and the zssc3154 evaluation kit with the zssc3154 mass air flow maf sensor board figure 3. A faulty mass air flow sensor decreases fuel efficiency. If the cautions are not followed, the air bag may open up unexpectedly, resulting in personal injury. Mass airflow sensor calibration evaluation international. When the oe fails, trust standard comprehensive maf sensor coverage premium quality. There are several designs of maf sensors, but the most common by far is the hot wire maf sensor. It is common to produce gains of 10 hp at the wheels on engines in the 2. Test is run at every reading of the mass air flow sensor frequency. A mass air flow air flow meterspeed density primer. Connect a scan tool to see the maf sensor parameter identification data pid information.
1184 1050 1415 808 10 1320 1181 74 625 1401 945 168 1268 685 623 469 1439 937 1048 1130 730 1360 819 11 595 1210 1445 795 145 335 1316 292 1294 271 371 447 1383 575 310 449 1124 872 551 664 822 861 1469 238