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.
