DTC Descriptor

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

DTC C056D 00: Electronic Control Unit Hardware Malfunction
DTC C056D 0F: Electronic Control Unit Hardware Signal Erratic
DTC C056D 18: Electronic Control Unit Hardware Low Signal Amplitude
DTC C056D 31: Electronic Control Unit Hardware Internal Checksum Error
DTC C056D 32: Electronic Control Unit Hardware General Memory Malfunction
DTC C056D 33: Electronic Control Unit Hardware Special Memory Malfunction
DTC C056D 34: Electronic Control Unit Hardware RAM Malfunction
DTC C056D 35: Electronic Control Unit Hardware ROM Malfunction
DTC C056D 36: Electronic Control Unit Hardware EEPROM Performance/Malfunction
DTC C056D 37: Electronic Control Unit Hardware Software Malfunction
DTC C056D 39: Electronic Control Unit Hardware Internal Malfunction
DTC C056D 3A: Electronic Control Unit Hardware Incorrect Component Installed
DTC C056D 3B: Electronic Control Unit Hardware Self-Test Malfunction
DTC C056D 3C: Electronic Control Unit Hardware Internal Communication Malfunction
DTC C056D 43: Electronic Control Unit Hardware EEPROM Incorrect Programming