DTC B1500: Fuel Sender Open Detected

DTC detecting condition :

Open circuit in fuel gauge circuit

Trouble symptom :

Defective fuel gauge.
Fuel level warning light blinks.

Failure detection pattern :

"Primary" (high-priority diagnosis)

Wiring diagram :

Combination meter system Ref. to WIRING SYSTEM>COMBINATION METER SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

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

BASIC INSPECTION .
Before performing the diagnosis, perform basic inspection. Ref. to COMBINATION METER (DIAGNOSTICS)>GENERAL DESCRIPTION>INSPECTION .
NOTE:
- Check the battery and its installation condition.
- Check the related fuse.
- Visually check that the related connectors are properly connected.
  Also, check the related ground terminal for looseness and corrosion.
Is the check result OK?

Yes : GO TO 2.

No : Repair the defective part.
CHECK DTC .
1. Turn the ignition switch to ON.
2. Read the DTC of [Combination Meter] using the Subaru Select Monitor. Ref. to COMBINATION METER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC B1500 displayed? (Current code)

Yes : GO TO 3.

No : GO TO 8.
CHECK COMBINATION METER .
Using the Subaru Select Monitor, check the following items in the [Active Test] of [Combination Meter]. Ref. to COMBINATION METER (DIAGNOSTICS)>ACTIVE TEST .
- Fuel Meter Operation
- Remaining fuel warning
Is the operation of [Fuel Meter Operation] and [Remaining fuel warning] OK?

Yes : GO TO 4.

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

After replacement, GO TO 10.
CHECK HARNESS (OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from the combination meter.
3. Disconnect the connector from the fuel level sensor.
4. Disconnect the connector from the fuel sub level sensor.
5. Using a tester, measure the resistance between the combination meter and fuel level sensor, between the combination meter and fuel sub level sensor, on the fuel level sensor and the fuel sub level sensor.
  Connector & terminal
  
  (i97) No. 25 - (R132) No. 1 :
  
  (i97) No. 26 - (L103) No. 2 :
  
  (R132) No. 4 - (L103) No. 1 :
Is the resistance 10 Ω or less?

Yes : GO TO 5.

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

After the repair, GO TO 10.
CHECK HARNESS (GROUND SHORT CIRCUIT) .
Using a tester, measure the resistance between the combination meter and chassis ground.

Connector & terminal

(i97) No. 25 - Chassis ground :

(i97) No. 26 - Chassis ground :

Is the resistance 10 Ω or less?

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

After the repair, GO TO 10.

No : GO TO 6.
CHECK FUEL LEVEL SENSOR .
Check the fuel level sensor as a single part. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL LEVEL SENSOR>INSPECTION .

Is the check result OK?

Yes : GO TO 7.

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

After replacement, GO TO 10.
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>INSPECTION .

Is the check result OK?

Yes : GO TO 8.

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

After replacement, GO TO 10.
CHECK CONNECTOR .
1. Disconnect the connector from the combination meter.
2. Disconnect the connector from the fuel level sensor.
3. Disconnect the connector from the fuel sub level sensor.
4. Check connectors for poor connections.
Is the check result OK?

Yes : GO TO 9.

No : Repair or replace the poor contact of connector.

After the repair, GO TO 10.
CHECK DATA MONITOR .
1. Connect the disconnected connectors.
2. Turn the ignition switch to ON.
3. Using the Subaru Select Monitor, read data of [Fuel level resistance] in the [Data Monitor] of [Combination Meter]. Ref. to COMBINATION METER (DIAGNOSTICS)>DATA MONITOR .
Does [Fuel level resistance] indicate 0 - 511.5 ohm?

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.

After the repair, GO TO 10.

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

After replacement, GO TO 10.
CHECK REPAIR .
1. Perform the inspection mode corresponding to DTC. Ref. to COMBINATION METER (DIAGNOSTICS)>INSPECTION MODE>OPERATION .
2. Confirm that DTC or cancel code is not stored and the malfunction is eliminated.
Is the check result OK?

Yes : Finish the diagnosis.

No : Perform the diagnosis according to the basic diagnostic procedure. Ref. to COMBINATION METER (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .