Tutorial: Parasitic drain

This month Steve Smith gives a superb tutorial on how to tackle parasitic drain.

Customer complaints surrounding flat batteries are common throughout the year with peaks during the winter season. Those who comment that their vehicle fails to start after standing for a couple of days must set alarm bells ringing with reference to parasitic drain.

Battery evaluation is normally taken care of using automated devices or better still, the PicoDiagnostics battery test procedure where we test not only the battery, but the starting and charging system in one hit. Once the above are confirmed we must then focus our attention on battery drain and parasitic current draw.

This test is often overlooked yet should conclude any customer complaints surrounding non-starts as a result of a discharged battery.

We can traditionally evaluate both a battery starting and charging system very quickly indeed but parasitic drain demands a prolonged test (30 minutes is not uncommon for a modern vehicle to shut down and move to sleep mode).

To continue reading Steve's parasitic drain tutorial, please view the article on our our website.

ScannerDanner (Premium) Videos

We have previously featured ScannerDanner's free videos in our newsletter. However, this month our readers are in for a real treat. Paul 'ScannerDanner' has allowed PicoScope Automotive newsletter readers see his latest videos free for a limited time. These two videos were destined to be locked for Paul's paid channel on YouTube, but are available to watch right now for a limited time! In a couple of weeks you will have to pay to view these videos on Paul's channel (along with lots of other worthwhile videos contained within it).

Pico's Steve Smith commented on Paul's latest videos:

Scanner Danner's video looks at a petrol engine and the effects upon the running condition as a result of a valve timing error. The vehicle is presented to Paul with multiple engine codes where the initial focus of the diagnosis is on the over fuel condition running rich.

The engine in question has been identified as having retarded camshaft timing (physical check) very early in the video but the main focus is how PicoScope has been utilised with minimal intrusion to confirm valve timing as the culprit.

Paul goes through the various techniques from Cam Crank correlation waveforms and referencing the waveform library (iATN) then on to relative compression and ignition correlation. The limitations of these captures are discussed where Paul moves onto pressure analysis.

Ultimately the decisive factor in the diagnosis of this vehicle comes with the use of the WPS in-cylinder waveform analysis whilst using the reference waveform features of PicoScope to highlight the errors between good and bad captures.

The video is exceptionally well-constructed with great tips along the way, not just about Pico but engine parameters and running conditions relative to a variety of faults.

Paul's videos can be seen on YouTube for a limited time:

How to test for a jumped timing chain or belt using Cam Crank signal and in cylinder pressure (part 1)

How to test for a jumped timing chain or belt using Cam Crank signal and in cylinder pressure (part 2)

Upcoming events and exhibitions

AutoNet: Cluj Napoca The Autonet Mobility Show is the most important automotive aftermarket exhibition in Romania, and one of the biggest in Hungary. The first event took place in 2012, in Cluj Napoca and, since then, has achieved a traditional status among exhibitors and visitors alike. Every year, one hundred of the most important auto spare parts, accessories and service equipment manufacturers gather to meet over 3500 workshop professionals who come to learn about the latest developments in their field and to benefit from special promotions. The Autonet Mobility Show has grown every year and established itself as the benchmark of automotive aftermarket events. AutoNet: Cluj Napoca 8th-9th May, 2015 Cluj Napoca, Romania
Autopromotec From May 20th to May 24th the 26th International Biennal Exhibition of Automotive Equipment and Aftermarket Products takes place in Bologna, Italy. In 1514 exhibitors from 51 different countries attended Autopromotec, with the show attracting over 100,000 visitors. Covering equipment and material for: car repair workshops, vehicle body repair shops, vehicle electricians, tyre retailers, car dealers, service stations, and car washes. Autopromotec 20th-24th May, 2015 Bologna Trade Fair Center, Bolgna, Italy
Stahlgruber show Trade visitors from the automotive industry will gain a comprehensive overview of innovations, new legal regulations, current products as well as services and support offered. The STAHLGRUBER exhibitions have more to offer than just information about day-to-day business: The growing market for vintage cars and modern classic cars or approaches to saving energy at car repair businesses are just some of the issues that are put in the limelight! New exhibitors, additional topics and the new STAHLGRUBER Centre of Excellence are other special features of the new 2015 exhibitions. A total of 180 well-known exhibitors from the industry make sure that a wide and interesting spectrum of information will be provided - for workshop owners and employees. Stahlgruber Show 30th-31st May 2015 Frankfurt, Germany