Reason:
Engine Air Filter Differential Pressure – Data Valid But Above Normal Operating Range – Moderately Severe Level

Effect:
Possible reduced engine performance.

Circuit Description:
The Engine Control Module (ECM) calculates the restriction across the air filter using sensors within the air management system.

Component Location:
Not Applicable

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the compressor intake air restriction is above a calibratible value.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
2) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
Plugged or highly restricted air filter can also possibly cause this fault to become active, especially at higher altitudes.

Possible Causes:
1) Inactive fault codes
2) Damaged air filter
3) Faulty ECM