DTC B1500: Fuel Sender Open/Short-Circuit Detection

DTC detecting condition: 

The fuel gauge circuit is open or shorted.

Trouble symptom: 

• Defective fuel gauge.
• Fuel level warning light blinks.

Wiring diagram: 

Fuel gauge system Ref. to WIRING SYSTEM>Fuel Gauge System>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DTC. 

   Using the Subaru Select Monitor, read DTC of combination meter. Ref. to COMBINATION METER (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1500 displayed? (Current malfunction)

   Yes: Go to  2.

   No: Go to  7.

2. CHECK COMBINATION METER. 
   1. Check the operation of combination meter using Subaru Select Monitor.
   2. From the «System Operation Check Mode», select «Fuel Meter Operation» and «Remaining fuel warning». Ref. to COMBINATION METER (DIAGNOSTICS)>SYSTEM OPERATION CHECK MODE .

   Is the operation of combination meter OK?

   Yes: Go to  3.

   No: Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .

3. CHECK HARNESS (OPEN CIRCUIT). 
   1. Turn the ignition switch to OFF.
   2. Disconnect the meter connector and the fuel sub level sensor connector and the fuel level sensor connector.
   3. Using the tester, measure the resistance between terminals.

   Connector & terminal

   (i10) No. 25 - (R59) No. 1:

   (i10) No. 26 - (R58) No. 4:

   (R59) No. 2 - (R58) No. 1:

   Is the resistance 10 Ω or less?

   Yes: Go to  4.

   No: Repair the open circuit of harness or replace harness.

4. CHECK HARNESS (GROUND SHORT CIRCUIT). 

   Using the tester, measure the resistance between terminals.

   Connector & terminal

   (i10) No. 25 - Chassis ground:

   (i10) No. 26 - Chassis ground:

   Is the resistance 10 Ω or less?

   Yes: Repair the short circuit of harness or replace harness.

   No: Go to  5.

5. CHECK FUEL SUB LEVEL SENSOR. 

   Check the fuel sub level sensor as a single part. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL SUB LEVEL SENSOR . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H6DO)>FUEL SUB LEVEL SENSOR

   Is the check result OK?

   Yes: Go to  6.

   No: Replace the sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL SUB LEVEL SENSOR . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H6DO)>FUEL SUB LEVEL SENSOR

6. CHECK FUEL LEVEL SENSOR. 

   Check the fuel level sensor as a single part. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL LEVEL SENSOR . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H6DO)>FUEL LEVEL SENSOR

   Is the check result OK?

   Yes: Go to  7.

   No: Replace the sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL LEVEL SENSOR . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H6DO)>FUEL LEVEL SENSOR

7. 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: Go to  8.

8. CHECK CURRENT DATA. 

   Using the Subaru Select Monitor, display «Fuel level resistance» from «Data monitor». Ref. to COMBINATION METER (DIAGNOSTICS)>READ CURRENT DATA .

   Does the data display 10 - 570 O?

   Yes: 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.

No: Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .