Conditions for Running the DTC

WARNING: This page is about a different car, the 2006 GMC Yukon XL, 2006 Chevrolet Suburban, and 2006 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

DTCs P0068, P0120, P0220, P2135 are not set.
The engine has been running for a length of time that is determined by the startup coolant temperature. The length of time ranges from 10-242 seconds.
The accelerator pedal angle is less than 1 percent when the engine speed is less than 1,200 RPM.
OR

The throttle angle is less than 20 percent when the engine speed is more than 1,200 RPM.
DTC P0108 runs continuously when the above conditions are met.