aaaa logo

Member of Australian Automotive Aftermarket Association

PRTC Council Member

4WD Council Member

Latest News

Testing EGR Systems (Exhaust Gas Recirculation) - Pt 2
September 2012

With the variety of EGR systems used for the control of NOx emissions it is important to understand the components operation, prior to carrying out any diagnostic or testing. (Refer to previous issues for EGR system operation).

Testing times for EGR systems

A defective component in the EGR system may have a very detrimental effect to the engine performance and therefore the emissions.

Strict emission laws and the malfunction indicator light generally illuminated when a system fault exists, require a prompt resolution.

1. Pneumatic EGR Valve System Component Tests

Note that vacuum supply to all components must be tested on the vehicle to eliminate misdiagnosis

Single diaphragm type EGR valve
Using a manual vacuum hand pump can verify movement of the valve and the condition of the diaphragm. This can be performed on or off the vehicle. Dual diaphragm types will vary in test procedure.

EGR valve with potentiometer feed back
Potentiometer resistance can be checked with the harness disconnected. Voltage test is preferred with the harness connected using a suitable scanner / scope or multimeter.

Electro-Pneumatic Vacuum Pump Valve
Using the vacuum pump can verify if the valve is sealed or leaking when not activated and if the valve opens when the solenoid is activated. Solenoid resistance can also be tested with an ohm meter.

Thermo Valve
Using the vacuum pump can verify if the valve is closed when cold and heating the unit with a heat gun should result in the valve opening above approximately 70 degrees Celsius.

2. Electric EGR Valve Test

The combination EGR valve and feedback system in this unit is controlled and monitored by the ECM and requires no external vacuum source to operate.

Note: This is a typical vehicle pin out configuration but this can vary for different vehicle models. Always refer to correct wiring diagram.

A suitable scanner can assist in testing this type of EGR valve by using the scanner program to activate the solenoid and also monitoring the feedback signal. The switching of a functioning valve can be audible when the engine is not running.

On later vehicles, renewing the EGR valve requires relearning by using program options in the scanner. That is the electric EGR valve must be adapted to the ECU.

Tips for troubleshooting EGR – Its Exhausting!
The most common cause of malfunctions in the EGR systems are stuck or blocked EGR valves due to excess carbon build up. This generally results in incorrect sealing between the exhaust and inlet and results in idling problems and poor performance.

In most cases the EGR valve is replaced but the cause of the excess carbon is not investigated, why?

Engine Management systems where an Intake Air Temperature (IAT) sensor is located directly in the inlet manifold can assist greatly is diagnosing leaking EGR valves.

That is, monitoring the IAT output signal from a cold start – idling condition, should not indicate rapid increase in intake air temperature.

This would be the case if the EGR valve was allowing exhaust gas to enter the inlet manifold when not required.

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