ENGINE (DIAGNOSTICS)(H4SO) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P0462 FUEL LEVEL SENSOR “A” CIRCUIT LOW

DTC DETECTING CONDITION:

Detected when two consecutive driving cycles with fault occur.

CAUTION:

After repairing or replacing the defective part, perform the Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

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1.CHECK SPEEDOMETER AND TACHOMETER OPERATION IN COMBINATION METER.

Does the speedometer and tachometer operate normally?

Repair or replace the combination meter.

2.CHECK INPUT SIGNAL OF ECM.

1) Turn the ignition switch to ON. (engine OFF)

2) Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B135) No. 25 (+) — Chassis ground (−):

Is the voltage less than 0.12 V?

3.CHECK INPUT SIGNAL FOR ECM (USING SUBARU SELECT MONITOR).

Read the data of fuel level sensor signal using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to “READ CURRENT DATA FOR ENGINE”.

Is the voltage less than 0.12 V by shaking the ECM harness and connector?

Repair the poor contact of ECM connector.

Even if the malfunction indicator light illuminates, the circuit has returned to a normal condition at this time. Temporary poor contact of connector may be the cause.

NOTE:

In this case, repair the following item:

• Poor contact in combination meter connector

• Poor contact in ECM connector

• Poor contact of coupling connector

4.CHECK INPUT VOLTAGE OF ECM.

1) Turn the ignition switch to OFF.

2) Separate fuel tank cord connector (R57) and rear wiring harness connector (R15).

3) Turn the ignition switch to ON.

4) Measure the voltage of harness between ECM connector and chassis ground.

Connector & terminal

(B135) No. 10 (+) — Chassis ground (−):

Is the voltage 0.12 V or more?

5.CHECK HARNESS BETWEEN ECM AND COMBINATION METER.

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from connector (i10) and ECM connector.

3) Measure the resistance between ECM and chassis ground.

Connector & terminal

(B135) No. 10 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the ground short circuit of harness between ECM and combination meter connector.

6.CHECK HARNESS BETWEEN ECM AND COMBINATION METER.

Measure the resistance between ECM and combination meter connector.

Connector & terminal

(B135) No. 10 — (i11) No. 1:

Is the resistance less than 10 Ω?

Repair or replace the combination meter.

Repair the open circuit between ECM and combination meter connector.

NOTE:

In this case, repair the following item:

Poor contact of coupling connector

7.CHECK FUEL TANK CORD.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from the fuel sub level sensor.

3) Measure the resistance between fuel sub level sensor and chassis ground.

Connector & terminal

(R59) No. 1 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the ground short circuit of fuel tank cord.

8.CHECK FUEL TANK CORD.

1) Disconnect the connector from fuel pump assembly.

2) Measure the resistance between fuel pump assembly and chassis ground.

Connector & terminal

(R59) No. 2 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the ground short circuit of fuel tank cord.

9.CHECK FUEL LEVEL SENSOR.

1) Remove the fuel pump assembly.

2) Measure the resistance between fuel level sensor and terminals with its float set to the full position.

Terminals

No. 3 — No. 5:

Is the resistance between 0.5 — 2.5 Ω?

Replace the fuel level sensor.

10.CHECK FUEL SUB LEVEL SENSOR.

1) Remove the fuel sub level sensor.

2) Measure the resistance between fuel sub level sensor and terminals with its float set to the full position.

Terminals

No. 1 — No. 2:

Is the resistance between 0.5 — 2.5 Ω?

Repair the poor contact of harness between ECM and combination meter connector.

Replace the fuel sub level sensor.