LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2005 >> Forester XT, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Engine (Diagnostics) (H4DOTC) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC P0183 Fuel Temperature Sensor "A" Circuit High Input
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0183 Fuel Temperature Sensor "A" Circuit High Input

DTC DETECTING CONDITION: 

CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode < Ref. to , OPERATION , Clear Memory Mode. > and Inspection Mode < Ref. to , PROCEDURE , Inspection Mode. >.

WIRING DIAGRAM: 

Fig 1: Wiring Diagram - Fuel Temperature Sensor Circuit (High Input)
G03806988Courtesy of SUBARU OF AMERICA, INC.
DTC P0183 DIAGNOSTIC PROCEDURE

Step Check Yes No
1 CHECK CURRENT DATA. 
  1. Start the engine.
  2. Read the data of fuel temperature sensor signal using Subaru Select Monitor or OBD-II general scan tool.
NOTE:
  • Subaru Select Monitor

    For detailed operation procedures, refer to "READ CURRENT DATA SHOWN ON DISPLAY FOR ENGINE" in SUBARU SELECT MONITOR .

  • OBD-II general scan tool

    For detailed operation procedures, refer to the OBD-II GENERAL SCAN TOOL Instruction Manual.

 Is the temperature less than -40°C (-40°F)? Go to step 2  . Repair poor contact.
NOTE: In this case, repair the following:
  • Poor contact in fuel pump connector
  • Poor contact in ECM connector
  • Poor contact in coupling connector
  • Poor contact in joint connector
2 CHECK HARNESS BETWEEN FUEL TEMPERATURE SENSOR AND ECM CONNECTOR. 
  1. Turn ignition switch to OFF.
  2. Remove the access hole lid.
  3. Disconnect the connector from fuel pump.
  4. Measure the voltage between fuel pump connector and chassis ground.

Connector & terminal 
(R58) No. 6 (+) - Chassis ground (-): 		 Is the voltage more than 10 V? Repair short circuit to battery in harness between ECM and fuel pump connector. Go to step 3  .
3 CHECK HARNESS BETWEEN FUEL TEMPERATURE SENSOR AND ECM CONNECTOR. 
  1. Turn ignition switch to ON.
  2. Measure the voltage between fuel pump connector and chassis ground.

Connector & terminal 
(R58) No. 6 (+) - Chassis ground (-): 		 Is the voltage more than 10 V? Repair short circuit to battery in harness between ECM and fuel pump connector. Go to step 4  .
4 CHECK HARNESS BETWEEN FUEL TEMPERATURE SENSOR AND ECM CONNECTOR. 
Measure the voltage between fuel pump connector and chassis ground.
Connector & terminal 
(R58) No. 6 (+) - Chassis ground (-): 		 Is the voltage more than 4 V? Go to step 5  . Repair harness and connector.
NOTE: In this case, repair the following:
  • Open circuit in harness between ECM and fuel pump connector
  • Poor contact in fuel pump connector
  • Poor contact in ECM connector
  • Poor contact in coupling connector
5 CHECK HARNESS BETWEEN FUEL TEMPERATURE SENSOR AND ECM CONNECTOR. 
  1. Turn ignition switch to OFF.
  2. Disconnect the connector from ECM.
  3. Measure the resistance of harness between fuel pump connector and ECM.

Connector & terminal 
(R58) No. 5 - (B136) No. 35: 		 Is the resistance less than 1 Ω? Replace the fuel temperature sensor. < Ref. to FUEL TEMPERATURE SENSOR . > Repair harness and connector.
NOTE: In this case, repair the following:
  • Open circuit in harness between ECM and fuel pump connector
  • Poor contact in fuel pump connector
  • Poor contact in ECM connector
  • Poor contact in coupling connector
  • Poor contact in joint connector
scientia non olet · About LEMON Manuals