P0068

DTC P0068: Throttle Body Airflow Performance

Circuit Description
The engine airflow measurements not based on throttle position are compared with throttle position based estimated airflow. If the ECM detects that measured airflow is much higher than the throttle based estimated airflow, a DTC will set.

Conditions for Setting the DTC
- Engine is running.
- No MAP or IAT fault exists.
- Difference between measured airflow and estimated airflow is greater than 9 g/s.

Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.

Conditions for Clearing the MIL/DTC
- The MIL will turn OFF after four consecutive validation cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- The DTC(s) can be cleared by using the scan tool.

Diagnostic Aids
An intermittent malfunction may be caused by a problem in the HO2S electrical circuit. Inspect the wiring harness and the components for an intermittent condition. Refer to Intermittents. Intermittents
If a DTC P0031 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was first set.

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Troubleshooting