Diagnostic Aids

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.

A leak in the reductant system can be located by inspecting for a build-up of crystallized diesel exhaust fluid (Reductant).
The reductant injector may temporarily stick after the engine is off for a short period and cause DTC P20EE or P2BAA to set. The reductant injector may unstick after exposure to elevated exhaust temperatures after the engine is restarted.
Water in the Reductant tank will cause DTCs to set.
Using the Reductant Injector Device Control, a ticking sound should be heard at the reductant injector.
Using fuel other than ultra low sulfur content fuel will cause this DTC to set.