aaaa logo

Member of Australian Automotive Aftermarket Association

PRTC Council Member

4WD Council Member

Latest News

Speed Sensors (SPS)

What Technicians need to know when diagnosing, testing and replacing speed sensors on vehicles.

These speed sensors may be used for monitoring multiple rotating components, depending on the amount of electronic and non-electronic control systems fitted to the vehicle.

Typically, a fault in a speed sensor may affect one or more of the following automotive systems:

  • Speedometer operation that may cause major engine management issues – if applicable.
  • Transmission issues with shift points and quality.
  • ABS /Traction control and Stability Control/ Hill descent system issues – if fitted.
  • Power Steering issues.
  • Cruise Control issues/prevention.
  • Idle stop / start system prevention.

Any sensor that influences so many automotive systems needs to urgent attention if suspected of being faulty.

Locating the suspect speed sensor is the first task for the technician as it may be located in a variety of places depending on make and model.


  • Transmission Input Speed. Transmission ECM monitors difference to engine RPM due to torque converter slip.

  • Transmission Output Speed. Transmission ECM monitors difference between input and output speeds during and after shift points.

Some Subaru models utilise three speed sensors on the transmission assembly to transmit speed signals to the TCM (Trans Control Module). The TCM processes these signals and outputs a signal that is used to drive the instruments and forward the road speed to the engine ECU.

Note: A stand-alone speedometer drive sensor unit may be driven by the output shaft of a manual or automatic transmission on some vehicles. This may mainly affect the speedometer operation.

  • Axle / Wheel Speed. Many later vehicles utilise the ABS wheel speed sensor as a multi utilised vehicle speed sensor for other systems. For more information on this type of speed sensor, please refer to Wheel Speed Sensor article.

  • Speedometer Cable Rotation. A reed switch that will open and close circuit by a rotating magnet – driven by the speedometer cable.

  • Note: This type of reed switch sensor operated by a rotating magnet may also be located in a transmission mounted unit where the magnet is driven by the output shaft.

Once the location of the sensor has been determined, the technician must identify the operating principal for the specific speed sensor. It may be one of the following types:

  • Analogue Signal Type Sensor. (Generally, on older vehicles)

The analogue type sensor is generally a magnetic variable reluctance type, incorporating a wire wrapped permanent magnet that induces a waveform output voltage when the toothed ring rotates (when the vehicle moves) and interrupts the magnetic field. The output signal alters in frequency as the output speed increases and decreases.

A suitable oscilloscope can quickly test the output signal quality if the sensor is suspect and is the preferred method. An Ohm meter can be used to check the resistance of the internal windings for short and open circuit. A voltmeter can indicate if a signal is present but not the most accurate test procedure for this sensor.

  • Digital Signal Type Sensor. (Most common type)

This digital sensor is generally known in the trade as a HALL type sensor. It generally requires 3 terminals to function but many hall type ABS wheel speed sensors (active types) only require 2 terminals due to new design and operational changes. It is important to ensure that the voltage supply to the HALL type sensors are correct as the output will be seriously affected.

Testing the Digital type sensor may be carried out directly at the sensor with a suitable oscilloscope or may be monitored utilising a suitable scanner with the related drive wheels raised and rotating.

Note: It is important to ensure that the related wiring and control units are operating correctly as any part of the circuitry may cause major systems malfunctions.

The Premier Auto Trade Sensor range includes almost 30 Speed Sensors (SPS) from the world’s leading manufacturers, covering almost 5 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

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