aaaa logo

Member of Australian Automotive Aftermarket Association

PRTC Council Member

4WD Council Member

Latest News

Mass Air Flow (MAF) Sensors

It is important for a Technician to identify the type of MAF sensor fitted to the vehicle and carry out the appropriate test procedure if it is suspected of being faulty.

There are generally two categories: Analogue MAF – Varying voltage output
Digital MAF – Frequency output.

Analogue MAF Sensor

These units range from a simple (minimum) 3 terminal sensor for measuring air flow only, to a multiple
connector sensor that integrates an intake air temp sensor and on some very early types a burn off circuit to clean the sensing wire. (Hot wire)

Analogue MAF signal.

Voltage output varies with air flow. Note: Generally low voltage output with low air quantity and increased voltage output as air flow increases.

Digital MAF sensor.

These units also range from a simple (minimum) 3 terminal sensor monitoring air flow only, to a comprehensive 8 terminal MAF unit for monitoring not only air flow but also including pressure, temperature and humidity.

Digital MAF signal.

Frequency output varies with air flow. Note: Generally low frequency output with low air quantity and increased frequency output as air flow increases.

Typical MAF sensor faults and effects on the vehicle performance.

  • Low output signal.
    • Will generally result in lean mixtures and driveability problems. Note: there are many other engine systems that can create lean mixtures and it is important to correctly determine if the MAF is the cause.
  • Internal MAF circuit faults.
    • Internal circuit faults generally cause intermittent engine stalling and tapping the MAF housing may result in a restart.
  • Dirt and carbon build up around the sensor element also affects the MAF output and vehicle driveability. (New MAF designs have reduced this problem).
    • Cleaning the element during a routine service generally improves vehicle performance but not always to a satisfactory level.
  • Connector and wiring faults effect the MAF output and may result in stalling or performance problems.
  • MAF damage due to backfire.
    • Generally, damage to elements are visible.

Testing procedures:

The test equipment required may vary for the vehicle being worked on.

  • Early vehicles – may not support a scanner reading and the oscilloscope may be the preferred test equipment.
    • Multi meter use is limited for output testing.
  • Later vehicles – generally require a suitable scanner to access MAF output information and for diagnosis purposes the Short and Long term trim information.
    • Graphing the MAF output is also achieved by most scanners for visual clarification.
    • An oscilloscope may also be used on the MAF output signal if required. The use of a multi meter is limited on most later vehicles.

Diesel MAF monitoring EGR valve operation.

When the EGR valve opens and closes, the air flow entering the intake through the MAF sensor will vary. The ECU will monitor the reduced intake MAF sensor air flow as the EGR valve opens and allows exhaust gas to enter the cylinder. The ECU also monitors the increased intake MAF sensor air flow as the EGR valve closes and restricts the exhaust gas.

Note: Many a Diesel MAF sensor has been unnecessarily renewed due to a MAF fault code logged – only to find the low air flow was caused by a non-sealing EGR valve.

Please be aware: After renewing the MAF on some vehicles, it may be recommended to perform the MAF sensor learning function after a MAF data reset has been carried out. Refer manufacturer recommendations and procedures.

A typical BT-50 Mazda Diesel procedure after renewing the MAF is shown below:

  1. Using a suitable scanner perform a MAF sensor data reset procedure to reset the adaption values in the ECU.
  2. Perform KOEO self-test procedure.
  3. Turn the ignition switch to OFF position.
  4. Wait for 5 secs.
  5. Start the engine.
  6. Perform KOER self-test procedure.
  7. Switch ignition OFF.

The Premier Auto Trade Emission range includes more than 240 Mass Air Flow (AFM) meters and sensors from the world’s leading manufacturers, covering over 11 million vehicle applications in Australia and NZ.

When you supply and fit products from Premier Auto Trade you can expect a product designed and tested to the vehicle manufacturer’s specifications offering OE form, fit and function. Premier Auto Trade distributes products throughout Australia via a network of specialised resellers and leading automotive groups.



Latest News

Tech Tips - Wheel Speed Sensors (WSS)

Positive Crankcase Ventilation (PCV) and Oil Separators

Common Rail Diesel Pumps (HDP)

Exhaust Gas Temperature Sensor (EGT)

Hose Clamps

MAP Sensors (Manifold Absolute Pressure)

Electric Water Pumps

Pulse Width Modulation (PWM)

Mass Air Flow Sensors (Hot Wire/Film)

Petrol Fuel Injector Replacement

Electronic Throttle Bodies (TBO)

Dual Petrol Injection Systems – Technical Tip

Wheel Speed Sensors – More than just ABS

PAT Expands Emission Sensor Range

PAT Racing & Performance Injector Range Upgrade

Coils ain’t Coils!


Oil Level and Oil Temperature Sensors Operation

Failed Air Temperature Sensors Symptoms

MAP Sensors Testing

TI Automotive Mustang Performance Pump

New ICON SERIES Hose Clamp Range

New Premium Sensors Ranges

Relay problems on vehicle

Test Equipment and Tools

Fuel Rail Sensors (FRS)

Failing Secondary Ignition

Testing Electric Fuel Pumps

Performance Fuel Rails and Filters

Testing CAM Angle Sensors (CAM)

Testing Electric Valve Solenoids (EVS)

Electronic Throttle Bodies

Performance Fuel Cells & Surge Tanks

Fault Finding Fuel Pressure Regulators (FPR)

Testing Variable Camshaft Actuators (VCA)

Testing Accelerator Pedal Position Sensors (APS)

Diagnosing Crank Angle Sensors (CAS)

Performance Regulators and Gauges

Differentiating Wheel Speed Sensors (WSS)

Mass Air Flow Sensors - Hot Film

Mechanical Fuel Pumps (MFP)

ICON Series Hoses

Particulate Matter Sensors (PMS)

Performance Fuel Injectors

Fuel Injectors (GDI)

DENSO Spark Plugs

Performance Fuel Pumps

Cooling Fan Switches (CFS)

Water Temperature Sensors (WTS)

Reverse Light Switches

Oil Temperature Sensors (OTS)

BMC Air Filters

Flasher Cans

Exhaust Pressure Sensors (EPS)

Power Steering Switches

Coolant Temperature Sensors (CTS)

Variable Intake Manifolds (VIM) and Intake Control Valves (ICV)

Oil Level Sensors (OLS)

Throttle Position Sensors (TPS)

Air Temperature Sensors (ATS)

Ignition – Condensers, Contact Sets, Distributor Caps and Rotors

Fuel System Accessories (FSA)

MAP Sensors (MAP)

Relays (REL)

HALL Sensors and Pickups (HAL)

Fuel Rail Sensors (FRS)

Speed Sensors (SPS)

New ICON Series Fuel Pump Range

New ICON Series Hose Range

Performance Range Increase Continues

PAT Oxygen Sensor Range Expands

PAT Expands Automotive Aftermarket Presence

Equipment and Tools

Electric Fuel Pumps (EFP)

Electric Valve Solenoids (EVS)

CAM Angle Sensors (CAM)

Ignition Modules (MOD)

Injector Service Components

Exhaust Gas Temperature Sensors (EGT)

Throttle Bodies

Knock Sensors

Ignition Coils

Fuel Injectors (Petrol)

Variable Camshaft Actuators (VCA) Oil control Valves

Accelerator Pedal Position Sensors (APPS)

Exhaust Gas Recirculation Valves (EGR)

Relocation of Sydney Distribution Centre

Wheel Speed Sensors (WSS)

High Tension - Ignition Lead Sets (ILS)

Suction Control Valves (SCV)

Mass Air Flow (MAF) Sensors

Crank Angle Sensors (CAS)

Fuel Pressure Regulators (FPR)

Oil Pressure Sensors

Exhaust Gas Oxygen Sensors

Shedding Light on Stop Light Switches

Ignition Distributors

Common Rail Diesel (CRD) Fuel Injectors

Idle Speed Control

New Distribution Centre Opening in ADELAIDE

New Distribution Centres Opening in PERTH and DARWIN

New Fuel Catalogue from Premier Auto Trade

BMC 4WD Air Filters Range Expands

New MVP Fuel Injector Range

PAT Developing Programs on Demand

New Premium Packaging for PAT

New Product Ranges Released By PAT

PlusQuip Test Equipment Range Expands

New Raceworks Catalogue

New Exhaust Gas Temperature Sensors

New Trade Catalogues from Premier Auto Trade

New Distribution Centre Opening in Adelaide

More European Parts from Premier Auto Trade

New PlusQuip Fuse Current Tester

PAT Pumped up!

Coils ain't Coils!

New PlusQuip Electronic EGR, Throttle Body, and Actuator Tester

New breed of High Performance products!

New Ignition Coil and Lead Set Kits

Wheel Speed Sensor Program Launched

Premier Ignition Lead Program Launch

Ignition Coils - Coils ain't Coils!

PlusQuip Battery Testers Launch

Premier Auto Trade Supporting Local Racing

Oval Trumpet Airbox (OTA) for 4WD applications from BMC Air Filters

BMC Air Filters NOW AVAILABLE from Premier Auto Trade

Premier Ignition Coils

MAP-013 and KNS-021 Now Back in Stock

BMC Air Filter partners with Premier Auto Trade

Premier Auto Trade opens South Australian Distribution Centre

Direct Fit Oxygen Sensor Range Hits 700

Automotive Electro-Mechanical Relays Types / Faults / Diagnosis

PlusQuip Tools and Equipment Launch

PlusQuip Fuel Line Repair Kit

PlusQuip Fuel Injector Service Kit

E85 High Performance with Premier Auto Trade

Testing EGR Systems (Pt 2)

New Delphi Fuel Module and Ignition Coil Range

Fuel Injector Service Components from Premier Auto Trade

Older News...

   privacy statement   terms of use   terms and conditions   sitemap   news  

© PremierAutoTrade