Condition 2

WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

Before the ECM can report DTC P0135 failed, DTCs P0030, P0031, P0032, P0101, P0102, P0103, P0121, P0122, P0123, P0130, P0131, P0132, P0221, P0222, P0223, P0335, P0336, P0338, P167A, P2237, P2243 and P2251 must run and pass.
The ignition 1 voltage is between 10.5-18 volts.
The ECT is more than -10°C (+14°F) at start up.
The HO2S is at operating temperature.
The ECM internal sensing element resistance test is enabled.
The fuel injectors are not disabled.
If the engine is operating and then the ignition is turned OFF, the engine must be OFF for at least 5 minutes before the next start-up for the diagnostic to run.
DTC P0135 runs continuously once the above conditions are met for more than 2 minutes.