Heater Core Could Be Issue for Volkswagen
This bulletin applies to 2013-2014 Volkswagen Beetle, 2010-2014 Golf and 2009-2014 Jetta Sportwagen vehicles, equipped with a 2.0L TDI engine.
DTC P2457 (exhaust gas recirculation cooler efficiency below threshold) may be stored. A reduction of flow inside the heater core will lead to reduced flow through the EGR cooler. This reduced flow can cause fault P2457 to set in the ECM.
If this DTC sets, 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. Replacing only the heater core will result in the vehicle returning with the same condition.
Drain the coolant per the Elsa procedure found in the repair manual.
Refill the cooling system using a 50/50 mixture of coolant and distilled water.
Start the engine and bring it to operating temperature. Let it idle for five minutes.
Repeat step 1 and drain the coolant.
Replace the heater core.
Refill the cooling system using a 50/50 mix.