Don't get caught with frozen DEF fluid

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Don't get caught with frozen DEF fluid


Meeting each new emission standard brings new challenges and often new technologies for technicians to master.

These systems ensure clean running but often come with new control modules, sensors and mechanical components. To ensure compliance with emission standards components with these systems will often put a vehicle into limp mode or at a minimum, set the malfunction indicator when not working correctly.

As more vehicles are being built to Euro 6 emissions standards, DEF (Diesel Exhaust Fluid) solutions like Adblue are now more commonplace. The urea-based diesel exhaust fluid itself is typically made up of 67.5% water and 32.5% urea. It can freeze.

Enter the DEF Heater, a component of the SCR or Selected Catalyst Reduction control environment.

A DEF control module is responsible for driving the DEF heater, reading a number of sensor inputs that can include the DEF tank temperature sensor, DEF supply pump temperature sensor and outside air temperature sensor, usually provided by the MAF sensor.

Based on these data the heater is instructed to defrost the urea-based fluid within the tank itself. This can be achieved by a heating element, or a valve allowing engine coolant to circulate through a water jacket in the tank.

The DEF heater is only one component of a proper SCR solution. It has multiple temperature inputs, running conditions and multiple modes of operation, from basic heating, thermal control, and start-up modes.

While we don’t get down to the temperatures seen in northern hemisphere population centres it certainly gets cold enough here to freeze DEF, making DEF heaters a valuable preventive measure.

Goss has some of the most common replacement components needed by vehicle repairers dealing with modern diesel emission solution repairs.

  • DEF heaters
  • EGR valve assemblies
  • EGT sensors
  • DPS pressure sensors
  • EGR coolers

Goss is a leading provider of genuine alternative aftermarket and original equipment parts with more than 75 years experience in sourcing and developing the our range.

Find your nearest Goss stockist, search catalogues, technical documents and other information online at 

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Don't get caught with frozen DEF fluid
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