P0326 and P0331

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.

Before the ECM can report DTC P0326 or P0331 failed, DTCs P0324, P0335, P0336, and P0338 must run and pass.
DTC P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, or P0393 is not set.
The engine coolant temperature (ECT) sensor is greater than 60°C (140°F).
The engine speed is greater than 2,200 RPM.
DTCs P0326 and P0331 run continuously once the above conditions are met for approximately 20 seconds.