Conditions for Running the DTC

WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

P0068

DTCs P0641, P0651, P1516, P2101, P2119, P2176 are not set.
The engine is running.
DTC P0068 run continuously when the above conditions are met.

P0121

DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0315, P0335, P0336 are not set.
The engine coolant temperature (ECT) is between 70-125°C (158-257°F).
The engine speed is more than 450 RPM.
The intake air temperature (IAT) is between -7 and +125°C (+19 and +257°F).
DTC P0121 run continuously when the above conditions are met.