Cruze

DTC P2297

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an open loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. The control module supplies the HO2S with a reference, or bias voltage of about 450 mV. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1.000 mV. This voltage will fluctuate above and below the bias voltage. Once sufficient HO2S voltage fluctuation is observed by the control module, closed loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases above bias voltage toward 1.000 mV indicates a rich fuel mixture. An HO2S voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.

The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter closed loop earlier and the control module to calculate the air to fuel ratio sooner.

The HO2S sensors utilises the following circuits:

The engine control module (ECM) detects that the HO2S Sensor 1 voltage is greater than 550 mV during deceleration fuel cut off mode.

DTC P2297 00 is a Type B DTC.

DTC P2297 00 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Engine running, observe the scan tool HO2S Sensor 1 voltage parameter. The reading should fluctuate above and below the range of 350-550 mV.
2. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

1. Ignition OFF, disconnect the scan tool and wait 60 s to ensure all modules are powered down.
2. Disconnect the harness connector at the B52 Heated Oxygen Sensor.
3. Ignition ON, verify the scan tool HO2S parameter is approximately 450 mV.

⇒	If more than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

4. Ignition ON, install a 3 A fused jumper wire at the B52 Heated Oxygen Sensor high signal circuit terminal 3. Toggle the jumper wire between the B52 Heated Oxygen Sensor low signal circuit terminal 4 and the battery voltage and also between the B52 Heated Oxygen Sensor low signal circuit terminal 3 and ground. Verify the appropriate scan tool HO2S parameter toggles between 0 mV and approximately 1 000 mV.

⇒	If the appropriate scan tool HO2S parameter does not toggle correctly, test the HO2S high signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

5. If all circuits test normal, replace the B52 Heated Oxygen Sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.