This bulletin applies to 2013-2014 Volkswagen Beetle, 2010-2014 Golf and 2009-2014 Jetta vehicles equipped with a 2.0L engine. The technician may find diagnostic trouble code (DTC) P2457 stored in the ECM (exhaust gas recirculation cooler efficiency below threshold). A reduction of flow inside the heater core will lead to reduced flow through the EGR cooler. This reduced flow can cause DTC P2457 to set in the ECM.
Check the inlet and outlet side temperature of the EGR cooler and the heater core. If there is a substantial difference in temperature, flush the cooling system before replacing the heater core. It is necessary to remove all hoses described in the Elsa repair procedure steps when draining the cooling system.
Drain the cooling system and refill using a 50/50 mix of coolant and distilled water. Start the engine and bring to operating temperature. Allow the engine to idle for 5 minutes. Drain the system again. Replace the heater core and refill the system.
