Re-saturating Chevy DEF pump filter

June 24, 2024
This bulletin applies to 2019-2020 Chevy Silverado 1500/2500/3500/4500/5500/6500 and LD vehicles equipped with a diesel engine.

This bulletin applies to 2019-2020 Chevy Silverado 1500/2500/3500/4500/5500/6500 and LD vehicles equipped with a diesel engine.

After replacing the DEF pump, you may find that the DEF pump won’t build pressure and one or more of the following DTCs may be set:

- P20E8 (reductant low pressure)

- P249C (excessive time to enter closed loop reductant injection control)

If it has been determined that after replacing the DEF pump and confirmed that the system is unable to build pressure, inspect the any leaks, loose connections or kinks in the supply line. After performing an initial leak test three times, if low pressure is present, this may be because the DEF pump filter has dried out.

Allow the vehicle to sit overnight with the new pump and DEF fluid in order to re-saturate the DEF pump filter. In the morning, perform the leak test three additional times. The pump should now be able to build pressure.

About the Author

Motor Age Staff

Motor Age has been publishing technical content for professional automotive technicians since 1899. Our writers have decades of experience and scores of ASE certifications, and they continue to teach new generations of technicians via classrooms all around the globe, as well as through the books and training manuals they've authored. 

Sponsored Recommendations

Garage Tip: The Value of System Solutions

Learn why inspecting related parts when repairing your vehicle can save you time and money. Avoid future failures and ensure satisfaction! Click to watch now.

Access the Best Learning Resource for Professional Mechanics

Get hands-on tips, updated repair instructions, mounting videos, failure diagnosis, and best practices for professional mechanics. Click to access essential technical info to ...

From the Basics to Innovations - Transmission Technical Training Videos

Explore Schaeffler's portfolio of transmission technical trainings for the LuK brand. Tailored for all skill levels, our modules cover basics to innovations. Click to learn more...

Clutch Release Problems - Diagnosis & Failure Analysis

Explore common clutch release problems and their causes, from hydraulic issues to mechanical faults. Understand diagnostics and solutions for optimal clutch performance.

Voice Your Opinion!

To join the conversation, and become an exclusive member of Vehicle Service Pros, create an account today!