Conditions for Running the DTC

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Conditions 1

Before the ECM can report DTC P2237 or P2240 failed, DTCs P0101, P0121, P0122, P0123, P0221, P0222, P0223, P0335, P0336, and P0338 must run and pass.
DTCs P0030, P0031, P0032, P0050, P0051, P0052, P0133, P0135, P0153, or P0155 is not set.
The ignition voltage is between 11-18 volts.
The engine is operating in Closed Loop.
The HO2S 1 heater is at operating temperature.
The ECM is commanding the lambda greater than 1.03 or less than 0.97.
Greater than 200 grams of exhaust gas has passed.
DTC P2237 and P2240 run continuously once the above conditions are met for approximately 8 seconds.

Conditions 2

Before the ECM can report DTC P2237 or P2240 failed, DTCs P0101, P0121, P0122, P0123, P0221, P0222, P0223, P0335, P0336, and P0338 must run and pass.
The ignition voltage is between 11-18 volts.
The engine is operating in Closed Loop.
The HO2S 1 heater is at operating temperature.
The ECM detects the internal HO2S 1 signal voltage is between 1.49-1.51 volts.
The ECM is commanding the lambda rich and then lean periodically with a change of greater than 2 percent.
DTC P2237 and P2240 run continuously once the above conditions are met for greater than 1 second.

Conditions 3

Before the ECM can report DTC P2237 or P2240 failed, DTCs P0101, P0121, P0122, P0123, P0221, P0222, P0223, P0335, P0336, and P0338 must run and pass.
The ignition voltage is between 11-18 volts.
The HO2S 1 heater is at operating temperature.
The ECM is commanding decel fuel cut-off for greater than 3 seconds.
DTC P2237 and P2240 run continuously once the above conditions are met for greater than 2 seconds.