Standard Ignition EFH204 Diesel Exhaust Fluid (DEF) Heater

DEF Heater for Volkswagen Passat

Standard Ignition EFH204 is a diesel exhaust fluid heater for select 2012-2014 Volkswagen Passat models. It is built with 2 connectors, 8 terminals, and blade-and-pin terminal design to support the DEF heating circuit in emission control service.

Key Features

• Diesel Exhaust Fluid (DEF) heater for emission control repair
• 2 connector design with rectangular and oval connector shapes
• 8 terminals with blade and pin terminal type
• No gasket included
• No hose included
• No mounting hardware included
• No O-ring included

Product Details

Standard Ignition EFH204 is an emission control component used in the DEF system on select Volkswagen Passat applications. This heater helps maintain DEF flow in cold conditions so the aftertreatment system can operate as intended. It cross-references Dorman - OE Solutions 904-378 for the same application. This part number, EFH204, is also listed among common interchange references used for the same vehicle coverage.

Common Issues This Part May Address

• DEF heater circuit fault codes
• Frozen or restricted DEF flow in low temperatures
• Emission system warning lights related to DEF heating
• Improper DEF system operation during cold-weather starts
• Failed heater connector or terminal-related electrical issues

Installation Notes

Verify connector shape, terminal count, and OE-style routing before installation. Inspect the DEF tank and related wiring for corrosion, damaged terminals, or contamination that could affect heater performance. Because no gasket, hose, mounting hardware, or O-ring is included, reuse or source any required service parts separately as needed for the repair.

Quality Assurance

Standard Ignition supplies emission control components for service replacement applications. Confirm fitment for 2012-2014 Volkswagen Passat before ordering, and match the part number EFH204 to the vehicle’s original DEF heater configuration.