Subaru released this TSB to explain the inspection, diagnosis and replacement procedures for the washer fluid level sensor. Applicable vehicles include the 2006 and later Tribeca, 2010 and later Legacy and Outback and 2012 Impreza.
1. Release the retaining clips and lower the left front splash guard to gain access to the washer fluid tank and fluid level sensor assembly.
2. Check for evidence of poor contact of the washer fluid level sensor wiring harness connector.
3. Does the low washer fluid warning light illuminate after draining the washer fluid? If yes, does the low washer fluid warning light go off after refilling the washer fluid? If yes, operation is normal. If no, proceed to Step 4.
4. Remove the wiring harness connector from the washer fluid level sensor, then measure the voltage of the vehicle-side connector using a DVOM. If voltage is about 8.5 V or more, proceed to Step 5. If not, check the harness carefully and verify the input/output signals to the combination meter and/or integrated unit as specified in the appropriate service manual. If the harness and signal checks are all within specification, combination meter and/or integrated unit replacement may be necessary.
5. Does the washer fluid indicator in the combination meter illuminate if you connect the terminals of the washer fluid level sensor wiring harness connector together? If yes, proceed to Step 6. If not, check the harness carefully and verify the input/output signals to the combination meter and/or integrated unit as specified in the appropriate service manual. If harness and signal checks are all within specification, combination meter and/or integrated unit replacement may be necessary.
6. Using a DVOM, measure the resistance of the washer fluid level sensor. With an empty tank (indicator on), resistance should be less than 10 ohm. With fluid present (indicator off), resistance should be 1 Mohm. If the measured resistance value is not within the standard, replace the washer tank assembly, as the fluid level sensor is not serviceable separately.