Electronic Diagnostics
Tracing and fixing faults in electronic engine management systems
The ubiquitous Ford Focus with diesel power has proved to be a popular and fuelefficient vehicle. For this feature,
Kim Henson and Edward Haggar take a close look at the thirdgeneration Focus equipped with the 2.0-litre Duratorq engine.
Believe it or not the Ford Focus has been a part of the automotive scene for nearly 22 years. First-generation models, replacing the long-running Escort, were introduced in October 1998, and were highly acclaimed for their dynamic performance and comfort. The Focus became a best-seller in markets globally.
Second-generation Focus models (from 2005) built on these sound foundations, presenting to potential buyers fresh styling, a raft of new technologies, a stiffer body structure and excellent results in EURONCAP safety tests.
In 2011 the third-generation Focus line-up was rolled out – notable features including new interior treatment, updated technologies and use of the new Ecoboost petrol engine.
For customers preferring diesel power, the Duratorq TDCI engines were offered in 1.6-litre or 2.0-litre versions. These common-rail, direct-injection motors incorporated twin-scroll turbochargers. They were the result of a joint venture with the PSA Group – and used in a wide range of models produced by Ford, Citroën, Peugeot and Volvo.
For this feature we are investigating a 163PS 2.0-litre Duratorq-powered Focus, dating from January 2014. Our guide to the diagnostic aspects of this Ford’s diesel motor and its Delphi DCM 3.5 V4 management system is Edward Haggar.
Preparation
At the outset it is worth establishing whether the fuel injector identification label/sticker is still attached to the top of the engine. If so, make sure you take a photo of it or make a note of the code numbers for future reference – before it eventually becomes illegible or detached from the motor over time.
New fuel injectors will need to be coded to the engine, using a diagnostic tool such as the Snap-on SOLUS Edge or other dealer-level equipment.
Battery condition is very important on this Focus. When installing a replacement battery, it must be of the correct type as specified by Ford, and it requires programming to the vehicle using diagnostic equipment.
With this Ford it is still possible to carry out many basic diagnostic checks using a multimeter – for example assessing the charging rate, supply voltage, etc. – so in this regard the car is quite user-friendly for the DIY mechanic.
As said, the diesel engine set-up was used in other makes/models, and it’s worth mentioning that from a diagnostic point of view – the equivalent Volvos
(for example) feature many functions and programming options, largely as a result of the Ford connection.
As with virtually all modern diesel vehicles, while carrying out basic underbonnet checks it’s worth checking the rubber pipework for signs of leaking, and security. It’s amazing how much difference a tiny hole in a pipe/hose will make to running quality and economy.
Regen DPF
Another feature of modern diesels, including this Focus model, is that periodically the Diesel Particulate Filter (DPF) needs to undergo ‘regeneration’ to rid it of accumulated debris, and to ensure efficient operation in terms of emissions and fuel consumption. On a vehicle that is used mainly on short runs in town, when the engine is seldom up to its optimum running temperature, the DPF can become choked much sooner than a car driven mainly on longer runs and at higher speeds, with the engine nearly always running at the ideal temperature.
The regen procedure is as follows:
1 Ensure that the engine is up to normal operating temperature.
2 Drive the car on a main road or motorway for at least 20 minutes, ensuring that the engine speed is between approx 1500 and 3000rpm. 3 The warning message and warning lamp extinguish when regeneration is completed. 4 Forced DPF regeneration can also be carried out using the manufacturer’s or equivalent diagnostic equipment.