Eclipse Diagnostics identifies engine fault

Eclipse Diagnostics identifies engine fault

Brett Edkins, Technical Manager at Eclipse Diagnostics, explains how to identify and correct an engine fault on a DAF XF E6.

The increasing technology imbedded in vehicles means that users are having to adopt increasingly sophisticated equipment to enable their engineers to maintain performance and effectiveness in the workshops and when out on remote call-outs.

The Eclipse Jaltest package has all the requirements to address the technological advances and as an example, the analysis of a DAF XF model shows how the Eclipse Jaltest package is becoming the go-to diagnostic solution for the commercial vehicle industry.

The problem

A DAF XF E6 has an engine and aftertreatment light on the instrument panel and it has failed to clear, as well as putting the vehicle into a torque reduction mode. As a result of this, the vehicle has had to be recovered to the workshop so that the engineers can use the Jaltest diagnostic equipment to identify and rectify the current faults with the vehicle.

Initial assessment

The engineer will firstly make an initial diagnosis of the vehicle’s engine and aftertreatment system. The engineer can do both of these systems at the same time using the Jaltest system scan where they can select certain ECUs to be scanned.

Once they have scanned the two ECUs, they can then check for any logged faults whether they are present or historic in the diagnostic memory. These will be able to assist Eclipse with rectifying the cause of the faults bringing the warning lights on.

After carrying out the system scan, the engineer had two active fault codes and there was one on the engine – P1496, which is an engine derate code that would be caused by a different fault code.

In the aftertreatment system, there was also an active code of U1849, which is the NOx sensor, before catalyst software verification incorrect. This fault code would also cause P1496 to come on. The fault code U1849 could be caused by an intermittent CAN line error or a faulty NOx sensor.

Jaltest analysis

The Jaltest software can take the fault analysis on the vehicle right down to the component as well as being able to show the necessary wiring diagrams, operation diagrams, and measurements for the specific vehicle.

In this case, the engineer can firstly check the location of the NOx sensor via the operation diagram or the system technical data. Once the engineer has found the location, they will then be able to check the wiring of the sensor using the Jaltest wiring diagram.


This is so they know what pins to test and what resistance and voltage they should be getting down the wiring and they will also be able to check for any brakes in the wiring. The engineer will also be able to see if the NOx sensor is reading through the measurement selection.

Correcting the fault

First of all, the engineer will check whether the NOx sensor is getting readings through measurement selection. Then the engineer will refer to the Jaltest wiring diagrams to check the NOx sensor wiring from sensor to ECU to check for any breaks or corrosion on the wiring and also will be able to view what resistances and voltages are correct to test the wiring.

If the wiring is non defective, then this would require the NOx sensor to be replaced. In this instance, the engineer found that all the wiring was non defective and it was the NOx sensor that was at fault. The engineer then replaced the NOx sensor with a Jaltest manufactured NOx sensor purchased from the Eclipse online shop.

If this was the first time that the engineer had carried out the procedure, then the industry leading Eclipse Vehicle Technical Support service is available to assist. This unique service is offered by Eclipse to all customers and can either assist the engineer in the problem solving process or utilise the remote assistance service.

Every Eclipse Testpad Extreme Pro PC is installed with Eclipse Assist software which allows the Eclipse Technical Support team to remotely access the customers Eclipse Testpad Extreme Pro PC via internet.

The team, with the customer’s agreement, can access the customer Testpad and assist with vehicle related support. This service allows the Eclipse Specialist to virtually sit next to the customer and see what the customer can see on screen, whilst taking control.

Eclipse looks after their customers

Eclipse has developed its business around the core philosophy of customer support from when the system is first purchased and throughout its life. That support begins with the software which is updated three times a year to reflect new models and more 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 Technical Support Service.

The Technical Support Service is a key part of the overall Eclipse package and together with Jaltest and the Eclipse Testpad Extreme+ sets them apart from others, helping to ensure that they remain the leading supplier of true multi-brand diagnostic software for all commercial vehicles.

About Eclipse

Eclipse is the largest supplier of multi-brand diagnostic products in the commercial vehicle aftermarket, with their innovative Eclipse Testpad Extreme Pro running Jaltest software helping many businesses to improve vehicle and machinery performance.

There are more than 3,000 Eclipse Jaltest packages 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.

For more information on the services on offer from Eclipse Diagnostics, click here.

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