BorgWarner is supplying the electric auxiliary thermal coolant pump (ATCP) installed in turbocharged compact SUVs introduced recently by a major Chinese automaker.

The pump features a brushless, no-leak, low-noise design with integrated microcontroller. In operation, it provides a continuous flow of coolant through auxiliary circuits, even when the engine is shut down. This helps auxiliary components maintain optimal operating temperature and contributes to longer component life, improved fuel economy and lower emissions. (And in electric and hybrid vehicles, an auxiliary pump improves driver comfort and keeps batteries at a constant temperature to maximize driving range.)

The ATCP drives coolant flow through auxiliary coolant circuits to help maintain optimal temperature for auxiliary components during normal vehicle operation. Image source: BorgWarner For the Chinese automaker, the 100-watt ATCP plays a critical role in turbocharger and indirect charge air cooling. And, the auxiliary pump helps to maintain cabin temperatures when the engine shuts down.

Turbochargers depend on reliable cooling, and as the degree of turbocharging increases, so does the need to cool the compressed air before it enters the engine. Indirect charge air cooling can offer numerous benefits over direct cooling with ambient air.

The low-temperature radiator needed for indirect charge air cooling provides a small installation depth compared to that of a conventional charge air cooler. This provides additional space in the front end. Also, since the cooler is installed relatively close to the engine, shorter charge air lines can be used. This reduces pressure loss by as much as 50% and makes more air available to the engine for combustion.

When the engine is running, the integrated microcontroller in the pump communicates directly with the engine controller to maintain optimum speed for engine conditions, from 0-100% depending on the application. When the engine is off, the pump transmits heat to a heater core (or heat exchanger) to keep auxiliary systems working at optimal temperatures. Unique features of the Borg Warner ATCP include an optimized brushless DC motor and floating rotor.