Conditions for Setting the DTC
WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
DTC C1138 03
The EBCM detects its supply voltage of less than approximately 7 V.
DTC C1138 07
The EBCM detects a supply voltage of more than 16.5 V.
DTC C1138 58
The Park Brake Controller (PBC) loses communication with the EBCM during park brake actuation.