Subaru of America, inc. (SOA) has determined that some affected vehicles listed below may require ECM reprogramming. The ECM logic for the air/fuel ratio circuit may not be broad enough to accept the signal parameters 01 the A/F ratio sensor.
Should the A/F ratio sensor signal repeatedly fluctuate beyond the parameters
of the ECM logic, the CHECK ENGlNE warning light / Maltunction indicator Lamp (Mil.) will illuminate steadily while the engine is running, advising the driver of a malfunction and the need to seek repair service. Reprogramming the ECM will broaden the allowable A/F ratio signal parameters and correct this condition.
This condition is a software issue and has no impact on vehicle emissions or driveability.
This service program will involve reprogramming the ECM on affected vehicles.
(*1) Legacy and Outback vehicles with the H6 engine or MT5 transmission are not affected.
(*2) Impreza WRX models are not affected.
* Various characters may occupy this position of the VIN.
Affected vehicles are identified in the VIN range chart.
NOTE: Prior to performing repairs, confirm coverage for potentially affected vehicles by using the Vehicle Coverage inquiry in the Dealer Communication System (DCS).