Aftermarket September 2022

T he use of Stop/Start systems on cars is changing the way ignition systems work, and creating new problems for garages to solve, as Julian Goulding, Marketing Manager at Delphi echnologies Aftermarket UK observed: “Tough legislation is pushing manufacturers to find ever- more sophisticated ways to reduce emissions. Stop/Start systems help achieve this by cutting the engine while the car is stationary, but a static engine can suffer from heat soak, where high temperatures generated by downsized, turbocharged engines are exacerbated by a lack of coolant flow. “Meanwhile, OEMs are striving for a bigger combustion spark, placing ignition coils under stress from both high under bonnet temperatures and tough electro-mechanical demands. Additionally, a repeated -20 °C to +100 °C heat- cycle exposes any weak links in the system.” Julian continued: “The conditions found under the bonnet of most modern cars are pushing materials to the limit. Coil packs are subject to extreme conditions as heat builds up during busy city traffic, and the starting cycle generates tough electrical loads. Delphi Technologies coil packs are designed for maximum magnetic power in every turn of the wire. Both primary and secondary coils are wound as smoothly and tightly as possible. Precise manufacturing ensures consistent wire lengths, reducing the chances of an insulation breakdown, and high-quality wire coatings resist imperfections that can cause failure.” Julian added: “Maximum fuel economy relies on optimal combustion, so Delphi Technologies has perfected so-called multi-charge ignition coils. These fire a rapid series of sparks every cycle, ensuring complete combustion. This can reduce emissions and improve fuel economy by up to 20% versus conventional coils offered by competitors.” Increasing number Also commenting on ignition coils, DENSO Europe Pan European Strategic Marketing Manager Fatiha Laauich said: “Due to the fact that they were the predominant ignition coils used by vehicle manufacturers between 2000 and 2010, stick coils, a design originally devised and patented by DENSO in 1997, are currently the most common ignition coil type seen in the aftermarket. Although since 2015, an increasing number of VMs have turned to COP coils, forecasts reveal that the stick will remain the mainstream coil in the aftermarket until at least the mid-2020s.” She continued: “Being long and narrow, the thermal stress in the axial direction of a stick coil body, caused by the heat shock environment it is exposed to, tends to be particularly high, so DENSO uses cushioning material for the top and bottom ends of the centre core to alleviate this problem.” Fatiha added: “In addition, although some ignition coils from other companies now have diagonal secondary 44 AFTERMARKET SEPTEMBER 2022 IGNITION www.aftermarketonline.net GET ROLLING... Ignition systems have changed as ongoing hybridisation and the move to EVs continues winding, the winding technology incorporated is often low, which also affects their durability.” For more information, visit: www.denso-am.eu Replacement and diagnosis The advance of technology is making working around the ignition system more complicated, as Autoelectro UK Sales Manager, Nick Hood, explained: “Technicians faced with replacing alternators should be wary of delicate data connections. Even with the arrival of smart alternators, 48V electronics and combined starter motor and alternators, the unit is installed the same way it was previously. However, advances in technology mean the technician is replacing a part that is more like computer equipment, meaning they need to be cautious. “The amount of overall electronics on a modern vehicle, if the cabling and everything was done in the same style it was 30 years ago, then the whole loom would be a lot bigger and heavier. Technology has improved in terms of the size of connection and the structure of cabling, which is great from a production perspective, but the practicality of removing and installing an alternator isn’t as robust.” Nick continued: “Autoelectro’s in-house remanufacturing facility, not to mention the three-and-a-half decades experience it has, means it is well-placed to investigate returns under warranty and offer advice on diagnosis. An issue could be something basic, like the tensioning or wearing of belts; however, a fault might be more complex, perhaps linked to the design of the vehicle in question. “For a starter motor, dual mass flywheel dust interference is a typical diagnosis, while for an alternator, problems are more difficult to identify because of the number of sensors that are relaying information to the electronic control unit. Each one of those links can create issues.” Above: Delphi ignition coil in the process of being fitted