P0685, P0686, and P0687

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

The ignition voltage is between 10-18 volts.
The engine speed is greater than 80 RPM.
The powertrain relay has been commanded ON and OFF.
The DTCs run continuously once the above condition is met.