This bulletin applies to diesel-equipped 2017-2020 Chevy Colorado, 2017-2020 Cruze and Express, 2018-2019 Equinox and 2017-2018 Silverado vehicles.
Technicians may find that after replacing the DEF pump, the pump won’t build pressure and one or more of the following DTCs may set: P20E8 (reductant low pressure) and/or P249C (excessive time to enter closed loop reductant injection control).
If it has been determined that after replacing the DEF pump and confirming that the system is unable to build pressure, inspect for 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 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.
