Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Def Tank Heater
The DEF pump assembly includes a DEF tank heater to thaw frozen DEF in the tank. The DEF heater is a series of heated strips that are designed to evenly thaw frozen DEF in the tank. The DEF temperature sensor detects the temperature of the DEF and determines if tank heater operation is necessary. The DEF pump will not prime until the DEF temperature has reached a sufficient temperature for dosing to occur. The DEF heater will activate and continue to heat the DEF based on pre-programmed values in the ECM.
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Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.