Join Date: Jun 2006
Location: Eastern ON Canada
Car: 07 OBW 2.5i D-4AT
Feedback Score: 7 reviews
If the AT Oil Temp light flashes while driving, it is indicating a control problem between the Transmission Control Module and the transmission itself. When the transmission fluid is getting too hot, the light will come on steady.
Also, in some cars, if a transmission problem can affect engine operation, or safety, it will also cause the CEL to come on as an additional warning.
Although your car might have an underlying TPS problem, I don't think this would cause the AT Oil Temp light to flash.
Unfortunately, basic diagnostic code readers usually can only read the engine/emissions-related codes stored by the engine control module -- not the codes generated and stored by the TCM, which would occur when the AT Oil Temp light flashes.
I would suggest checking with Autozone to see if their diagnostics reader can read Subaru transmission codes applicable to your model year. If not, you might have to take the car to a dealer to check. (There was a posting here some time back about being able to read the codes using a procedure that would cause the AT Oil Temp light to flash in a particular sequence corresponding to the stored code. A seach might find it, or perhaps someone can post the procedure here .)
I would add that transmission control problems have, in some cases, been isolated to bad connections in the transmission control harness connectors.