Conditions for Setting the DTC

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The system tests the lock solenoid circuits by checking for unwanted voltage.
The underhood fuse block supplies B+ on the battery positive voltage circuit and reads the voltage back on the lock solenoid control circuit.
If the TCCM detects a low voltage return when a high voltage is expected, or a high voltage return when a low voltage is expected, the DTC is logged.
The fault must remain current for 1 second to set the DTC.