DTC B1507 External Air Temperature Open/Short-Circuit Detection

DTC detecting condition:

Open or short circuit in ambient sensor

Trouble symptom:

Defective ambient temperature display
Defective air conditioner operation

Wiring diagram:

Air conditioning system Ref. to WIRING SYSTEM>Air Conditioning System>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CHECK DTC .
Read the DTC of the combination meter using the Subaru Select Monitor. Ref. to COMBINATION METER (DIAGNOSTICS)>Read Diagnostic Trouble Code (DTC) .

Is DTC B1507 displayed? (Current malfunction)

Yes Go to 2 .

No Go to 6.
CHECK CURRENT DATA .
Using the Subaru Select Monitor, display the «Ambient air temperature» from {Data Monitor}. Ref. to COMBINATION METER (DIAGNOSTICS)>Read Current Data .

Is data displayed?

Yes System is normal.

No Go to 3 .
CHECK HARNESS .
1. Turn the ignition switch to OFF.
2. Disconnect the combination meter connector and ambient sensor connector.
3. Using the tester, measure the resistance between terminals.
  Connector & terminal
  
  (i10) No. 36 - (F78) No. 2:
  
  (i10) No. 27 - (F78) No. 1:
Is the resistance 10 Ω or less?

Yes Go to 4 .

No Repair the open circuit of harness or replace harness.
CHECK HARNESS .
Using the tester, measure the resistance between terminals.

Connector & terminal

(i10) No. 36 - Chassis ground:

(i10) No. 27 - Chassis ground:

Is the resistance 10 Ω or less?

Yes Repair the short circuit of harness or replace harness.

No Go to 5 .
CHECK AMBIENT SENSOR .
Perform the inspection of ambient sensor unit. Ref. to HVAC SYSTEM (HEATER, VENTILATOR AND A/C)>Ambient Sensor>INSPECTION .

Is the check result OK?

Yes Go to 6 .

No Replace the sensor.
CHECK CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect connectors.
Is there poor contact of connector?

Yes Repair or replace the poor contact of connector.

No A temporary change of voltage occurred.