Brett Edkins, technical manager at multi-brand diagnostics specialist Eclipse, explains how to identify and correct a variable geometry turbo fault on a DAF LF Euro VI.
Eclipse’s Testpad Extreme Pro with Jaltest software helps many businesses to improve vehicle and machinery performance. More than 3,000 Eclipse Jaltest packages are in use covering a wide range of commercial vehicles at customer locations both in the UK and internationally.
Identifying faults on many modern commercial vehicles is increasingly difficult given the rising levels of technology employed by manufacturers across all aspects of the vehicles, including trailer units.
This means users are having to adopt increasingly sophisticated equipment to enable their engineers to maintain performance effectiveness in the workshops, and when out on remote callouts.
The Eclipse Jaltest package has all the requirements to address the technological advances. As an example, the analysis of the variable geometry turbo (VGT) on a DAF LF Euro VI model shows how the Eclipse Jaltest package is becoming the go-to diagnostic solution for the commercial vehicle industry.
A DAF LF has broken down at the roadside due to lack of power and the engine management light is illuminated on the dash. There are many possible causes, therefore the need for diagnosis is essential for identifying the fault.
The engineer firstly carries out a diagnosis of the engine management system to check for any current or stored fault codes, which guides them to the cause of the engine management fault.
One active fault code is present in the engine management system which Jaltest has identified – fault code 641-12. This fault code points an internal VGT error. This requires the vehicle to be recovered back to the workshop.
Once in the workshop, the engineer is able to look further into the fault with Jaltest and go through a step-by-step procedure of checking the present fault code, including wiring checks, activation and many more guided steps.
The engineer tests all the wiring with the help of the Jaltest step-by-step guided diagnosis and finds the wiring to be non-defective. As a result of this, the VGT will need replacing.
Jaltest has the complete guide for replacing the VGT from disassembly to assembly; this will help with aligning certain components when removing the VGT and ensuring it is done correctly. When the engineer has replaced the VGT, they need to carry out a calibration on it. This can also be done via Jaltest.
Clearing the fault
Once the calibration has been performed successfully, the code will have changed to an inactive fault, and the engineer is now able to clear the code from the ECU memory which will then clear the engine light from the dash and take the vehicle out of the derate mode, allowing the engineer to road test the vehicle.
Eclipse has developed its business around the core philosophy of customer support, from when the system is first purchased and throughout its life. That begins with the software, which is updated three times a year to reflect new models and additional information as it becomes available, and continues with the Eclipse support services.
A range of features and services are available, including a comprehensive training package which also includes full training programmes held at the Eclipse Training Centre, and cover from the vehicle and IT technical support service, a key part of the overall Eclipse package. www.eclipse-tech.co.uk.