Diagnostics and Repair of 48V Starter-Generators with MSG Equipment
Modern cars are becoming increasingly technological and environmentally friendly. One of the technologies contributing to this is "mild hybrids" (MHEVs), which use a low-voltage 48V electrical system.
The popularity of mild hybrids is continuously growing, driven by three factors:
• For manufacturers, it is the simplest and most cost-effective way to meet current environmental standards for emissions.
• The market price of MHEV hybrid cars is lower compared to other types of hybrid vehicles, making them more attractive to price-sensitive consumers.
• The operation and maintenance of mild hybrid cars do not differ from those of conventional internal combustion engine (ICE) vehicles.
The most important element of MHEV vehicles is the starter-generator, which performs a dual function: it acts as a starter to start the engine and as a generator to produce electricity. The most widespread design variant of the mild hybrid uses a Belt Starter Generator (BSG).
Unfortunately, many owners of MHEV vehicles with a 48V belt starter-generator have encountered generator failures. A failure of the 48V starter-generator can lead to a blockage of the 48V electrical network, discharge of the lithium-ion (Li-Ion) battery and the 12V battery, causing the car to lose its ability to move under its own power.
Repairing the 48V starter-generator: a viable alternative to buying a new unit
For a long time, the only way to address a 48V belt starter-generator malfunction was to replace it with a new one, which costs a significant amount. The alternative of buying a used 48V generator was unacceptable due to high risks:
• The technical condition of a used 48V alternator was unknown because there was no appropriate diagnostic equipment available at the time.
• There were no guarantees that a used 48V starter-generator would work for a long time since its lifespan might have already been exhausted.
The situation with faulty 48V belt starter-generators has now changed dramatically. Diagnostic equipment capable of fully diagnosing 48V alternators, such as the MS005A test bench, is now available. Additionally, spare parts for the power electronics of the 48V alternator—typical faults of these units—are available for purchase, and these spare parts are more reliable than the original ones.
MSG Equipment specialists have managed to develop the MS005A test bench, which provides the ability to diagnose 48V belt starter-generators in both alternator and starter modes, as well as the ability to check the generator control unit using a diagnostic scanner. Currently, the MS005A test bench can diagnose 48V alternators in the following vehicles:
• AUDI: A6/A7/A8/Q7/Q8 with MHEV 3.0TDI and 3.0TFSI engines;
• BMW: 3 Series, 5 Series, X3 with B47 MHEV and B48 MHEV engines;
• FORD: Focus IV/Fiesta VIII/Puma II;
• FORD TRANSIT CUSTOM with 2.0 ECO HYBRID engine;
• HYUNDAI: Tucson IV;
• KIA: Sportage V.
In addition to diagnosing the 48V starter-generator, MSG Equipment offers theMS800A tester for diagnosing and subsequently restoring the 48V lithium-ion battery.
