I have a 2005 Subaru Legacy with 18,000 miles. The check engine light came on during a very cold morning (-5F). Using an OBDII flash code reader, it stated I had a (P0131 Front oxygen (A/F) sensor circuit range/performance problem (low input) message. In addition, the cruise light flashes at the same time and does not engage. After I had erased the code, my cruise control did work again. The same flash code remerged after a few minutes.

 

What are my next steps to asses and fix the problem?

Mike

I have a 2005 Subaru Legacy with 18,000 miles. The check engine light came on during a very cold morning (-5F). Using an OBDII flash code reader, it stated I had a (P0131 Front oxygen (A/F) sensor circuit range/performance problem (low input) message. In addition, the cruise light flashes at the same time and does not engage. After I had erased the code, my cruise control did work again. The same flash code remerged after a few minutes.

 

What are my next steps to asses and fix the problem?

Mike

 

same thing you should have done the first time, take it to the dealer. The car is still under warrenty, let them figure it out.

You may have a lazy 02 sensor, the car may not be warming up properly to make the sensor happy.

No one likes to get out of bed when its -5F including cars.

 

 

nipper

bump

In the Subaru Drive-By-Wire, the cruise control is a co-processor built into the ECU. When the Cruise control flashes, it means either the ECU stored a cruise control error code, OR it has been disabled by the ECU detecting a MAJOR code ( one that flashes the CEL like a misfire, or one that keeps the CEL Illuminated ). Other minor stored codes will not disable the cruise.

 

So armed with this knowledge, The Cruise Control can flash without the CEL illuminated. The cruise function is disabled and a cruise related code is stored. OR Any error that illuminates the CEL will also disable the cruise and make it flash also.

 

External to the ECU for cruise function ONLY is the switch itself, Off/On and set/resume functions are all on the same 'stick' on the steering wheel. ( no more separate cruise switch on the dash board ), the brake cancel switch, and the clutch cancel switch. All other sensors and switches which the cruise co-processor monitors are also used by the ECU's main processor.