FixVault

Check Engine Coolant Temperature Sensor.

WARNING: This page is about a different car, the 2005 Subaru Outback and 2005 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
ENGINE COOLANT TEMPERATURE SENSOR SPECIFICATION

Step Check Yes No
1. CHECK COMMUNICATION ERROR DISPLAY. 
  1. Set the ignition switch to ON.
  2. Check that the error code is displayed in odo/trip meter.
Is the error code "Er xx" displayed in odo/trip meter? Check the communication circuit. < Ref. to , COMMUNICATION ERROR DISPLAY , INSPECTION, Combination Meter System. > Go to step 2. 
2. CHECK ENGINE COOLANT TEMPERATURE SENSOR. 
Check the engine coolant temperature sensor. < Ref. to BASIC DIAGNOSTIC PROCEDURE .> < Ref. to BASIC DIAGNOSTIC PROCEDURE .> < Ref. to BASIC DIAGNOSTIC PROCEDURE .> < Ref. to BASIC DIAGNOSTIC PROCEDURE . >
Is the engine coolant temperature sensor OK? Replace the meter case assembly. Replace the engine coolant temperature sensor.