Nissens explains the climate comfort system in new energy vehicles

Step-by-Step Diagnostics

As more new energy vehicles (NEVs), which include hybrid and electric vehicles, take to the roads, more will come into the workshop for routine climate system service, maintenance, or repair. However, the technicians undertaking this work need to be aware that they require special handling and safety procedures, as well as specialist knowledge to complete it successfully.

Using the thermal system as an example, many NEVs rely on a heat pump solution, which is an advanced system compared to a standard air conditioning (AC) loop.

Learn the heat pump system 

Unlike the AC in a conventional vehicle, the heat pump-based system is capable of both heating and cooling. It also manages the temperature of the vehicle's electric motor, battery pack and power electronics. In fact, the system functions as the vehicle's thermal management system and helps the car conserve battery life and extend its total range. 

Servicing the heat pump

Although some service procedures are similar to those of conventional vehicles, remember that hybrid and electric AC systems operate as thermal management systems, which means they must be fully functional in all seasons, not only for comfort, but also to ensure the correct operation of other systems. In fact, many NEVs will not start if the AC system is malfunctioning because of the risk of damage to the battery and the electric drive components. So, regular system maintenance is crucial. 

Common Problems

The most common failures include leakages, improper compressor lubrication, inner loop contamination and compressor burnout. Lower system performance or a total system failure are consequences of not addressing these problems quickly. 

Initial Inspection

Start any NEV's heat pump system inspection like any other conventional AC system, so first, check to ensure the system is working according to the set parameters. Study the manufacturer's guide on the number of heating/cooling functions and test them one by one, but keep in mind outside temperature can affect how the refrigerant flows through the system. If the system is functioning correctly, the valves that steer flows in the loop will open or close relative to ambient temperature. If it isn't, there's a risk that components could break down.

Never stop learning

NEVs will soon become commonplace in the aftermarket, so the ability of the independent sector to troubleshoot and fix their climate control systems and carry out routine maintenance will be vital for its future viability. 

Nissens Automotive publishes a great deal of learning resources regarding NEV climate systems, including how to flush the heat pump loop or replace the HV AC compressor. It will continue with more NEV-related stories, all of which can be accessed, alongside many more technical articles, via its expert knowledge portal at: www.nissens.com/experts