Functional description

The low temperature EGR cooler must be blocked against flow. When the engine is cold, the coolant must warm up as quickly as possible to keep emissions low. For this purpose, the additional cooling circuit is also kept closed.

When de-energized, the changeover valve of the low temperature EGR cooler is closed towards the low temperature EGR cooler. Engine control only activates the changeover valve once the low-pressure EGR cooler activates. The changeover valve switches to the additional coolant circuit.

Fig 1: Changeover Valve And Low Temperature EGR Cooler

Courtesy of BMW OF NORTH AMERICA, INC.