aaaa logo

Member of Australian Automotive Aftermarket Association

PRTC Council Member

4WD Council Member

Latest News

HALL Sensors and Pickups (HAL)

What the technician needs to know about diagnosing and testing HALL Sensors and Pickup Coils located in the Ignition distributor of a vehicle.

Note: HALL Sensors in general.

HALL sensors are widely used to monitor rotations and movement of components on many operating and management systems of the modern vehicle. HALL sensors may produce one of three output signals depending on system requirements.

  1. Square wave signal with varying frequency as rotating shaft speed increases or decreases. Commonly utilised for rotating component signals such as Crank Angle Sensors located inside or external of the distributor or similar rotating application.

  2. Square wave Pulsed Width Modulation (PWM) signal generally utilised on sensors with limited movement such as Throttle Position Sensors (TPS) and similar.

  3. Analogue output signal generally utilised on sensors with limited movement such as Throttle Position Sensors (TPS) and similar.

Ignition Distributor HALL sensors. (Varying frequency Digital signal type)

One of the more common areas for its application on vehicles fitted with Ignition Distributors is to monitor the Ignition distributor shaft rotation and the shaft position in relation to the crank shaft.

This is required by the Engine ECU to assist in Ignition and fuel control.
Typically, there are three wires required in the circuit for correct HALL sensor operation.

The HALL signal may be used directly by the Ignition Module as a trigger to switch the Ignition coil on and off or by the ECU to control ignition coil operation via a power transistor. Either way, the HALL output signal does not alter and is tested similarly.

Typical Oscilloscope signal taken at distributor at constant rotational speed.

This is the preferred testing method for a square wave signal. (Multi meters are not utilised for this test.)
Resistance readings for this type of sensor are not applicable.

Dual HALL Sensors located in Distributor.

Some vehicles utilise two HALL sensors inside the distributor to monitor the shaft speed for the ECU as performed by a typical Crank Angle Sensor (CAS) and also to monitor the TDC position for cylinder number one as performed by a typical Cam Angle Sensor.

Typical 5 Litre VT Commodore Distributor HALL Sensor.

A fault in the HALL sensor “circuit” generally results in a nil or intermittent output signal which generally causes a difficult or no start condition. The Power supplies and ground suitability must be checked prior to any thought of replacing the HALL sensor.
In many cases, it may be financially viable (for cost or time saving) to renew the complete distributor rather than replacing the HALL sensor on its own. The condition of the distributor should guide the Technician on the path to follow.

Ignition Distributor Pickup Coil Sensors. (Inductive Type)

Many earlier distributors utilised the inductive type pickup coil sensor instead of a HALL sensor as a trigger for the Ignition Module or ECU to control the Ignition coil operation. Generally, the ignition module will not function if it receives an incorrect type signal, so it is important to match the module to the type of trigger signal required.

Many Distributors have multiple pickup coils for Crank and Cam RPM monitoring and also cylinder position monitoring depending on the engine management system utilised.

Testing the inductive type signal again requires a suitable oscilloscope but there are necessary conditions prior to any testing.

  • Ensure the air gap between the reluctor and the reluctor wheel is correct as this affects the output Signal strength.
  • Ensure the coil windings resistance readings is acceptable. (refer manufacturers specs as they vary dramatically)

  • Ensure shaft rotation is true to ensure even output signals.
  • Ensure the magnet strength is acceptable.

Note the difference in amplitude on the captured screen below of typical pickup coil signals.

  • The lower amplitude relates to a greater air gap creating a weaker signal.
  • Beware of insufficient air gap that can cause physical mechanical damage.
  • Excessive differences in amplitude may cause misfiring and or hard starting.

Note: The inductive coil windings are polarity sensitive. The two wires must be connected to the correct terminals to ensure the module controls correct ignition coil spark timing. Incorrect polarity would result in the ignition coil spark being excessively advanced or retarded.

The Premier Auto Trade Sensors range includes almost 40 HALL Sensors from the world’s leading manufacturers, covering almost 200,000 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