[Blue Angel]

For those interested, here's the condidions surrounding the P0116 code.

Running the DTC:
-Ignition is ON
-DTCs P0112, p0113, P0116, P0117, P0118, P0128, P0502, P0503 are not set
-Start up IAT (Intake Air Temperature) is greater than -7C (+20F)
-Engine is turned OFF for greater than 10 hours
-DTC P0116 runs once per drive cycle when the above conditions are met

Setting the DTC:
-Start up ECT (Engine Coolant Temperature) is greater then the IAT by more than 100C (180F)
OR
-Start up ECT is greater then the IAT by more than 15C (27F), then the vehicle is driven over 24 km/h (15 MPH) for 400 seconds, during which time the IAT does not fall by more than 8C (14F). If IAT falls more than 8C (14F) in that time, a block heater is detected and the test is aborted.
-DTC is set upon two consecutive drive cycle test failures

I'm not sure what happens after the DTC is set? Does the computer ignore the ECT sensor reading and go into some sort of limp mode? Does it soldier on using the values returned by the (apparently faulty) sensor? I'm not sure... perhaps a GM tech could look into this for us?