DTC B14EC: Humidity Sensor Circuit Open

DTC detecting condition:

Temperature and humidity sensor circuit is open.

Trouble symptom:

Proper outlet air temperature cannot be kept.

Wiring diagram:

Air conditioning system Ref. to WIRING SYSTEM>AIR CONDITIONING SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to AIR CONDITIONER (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .

CHECK CONNECTOR .
1. Check connecting condition of the A/C control panel connector and the temperature and humidity sensor connector.
2. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC B14EC displayed? (Current malfunction)

Yes : Go to 2 .

No : Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
CHECK TEMPERATURE AND HUMIDITY SENSOR .
1. Turn the ignition switch to OFF.
2. Disconnect the temperature and humidity sensor.
3. Short the connector (i173).
4. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC B14ED displayed? (Current malfunction)

Yes : Replace the temperature and humidity sensor. Ref. to AIR CONDITIONER>TEMPERATURE AND HUMIDITY SENSOR .

No : Go to 3 .
CHECK HARNESS .
1. Turn the ignition switch to OFF.
2. Restore the temporary shorted lines made in step 2.
3. Turn the ignition switch to ON.
4. Using a tester, measure the voltage between terminals in temperature and humidity sensor connector.
Connector & terminal

(i173) No. 3 (+) - (i173) No. 2 (-):

Is the voltage 4.5 - 5.0 V?

Yes : Go to 4 .

No : Repair or replace the open circuit of harness.
CHECK HARNESS (OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from the A/C control panel.
3. Using a tester, check the continuity between the A/C control panel connector and temperature and humidity sensor connector.
Connector & terminal

(i173) No. 2 - (i88) No. 14:

(i173) No. 3 - (i88) No. 33:

Is there continuity?

Yes : Replace the A/C control panel.

No : Repair or replace the open circuit of harness.