Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
I've seen a number of these trucks in for this exact error message recently. 90% of them need a new DEF tank because of a clogged reductant filter.
Are you getting any trouble codes?
No trouble codes, any drivability issues? Has the latest PCM flash been performed? GM released a recent reflash to address random DEF quality error messages.
I just wanted to check whether you still need help with this.