ENGINE (DIAGNOSTICS)(H4DOTC DIESEL) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P0192 FUEL RAIL PRESSURE SENSOR CIRCUIT LOW

DTC DETECTING CONDITION:

Immediately at fault recognition

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK CURRENT DATA.

1) Start the engine.

2) Read the data of common rail pressure signal using Subaru Select Monitor or general scan tool.

NOTE:

• Subaru Select Monitor

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

• General scan tool

For detailed operation procedures, refer to the general scan tool operation manual.

Is the measured value less than 0 MPa (0 mmHg, 0 inHg)?

Even if DTC is detected, 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 may be the cause.

2.CHECK COMMON RAIL PRESSURE SENSOR POWER SUPPLY.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from the common rail pressure sensor.

3) Turn the ignition switch to ON.

4) Measure the voltage between the common rail pressure sensor connector and the engine ground.

Connector & terminal

(E126) No. 3 (+) — Engine ground (−):

Is the voltage 4.5 V or more?

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit in harness between ECM connector and common rail pressure sensor connector

• Poor contact of ECM connector

• Poor contact of coupling connector

3.CHECK HARNESS BETWEEN ECM AND COMMON RAIL PRESSURE SENSOR CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from ECM.

3) Measure the resistance of harness between ECM connector and common rail pressure sensor connector.

Connector & terminal

(B134) No. 46 — (E126) No. 2:

Is the resistance less than 1 Ω?

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit in harness between ECM connector and common rail pressure sensor connector

• Poor contact of coupling connector

4.CHECK HARNESS BETWEEN ECM AND COMMON RAIL PRESSURE SENSOR CONNECTOR.

Measure the resistance between ECM connector and chassis ground.

Connector & terminal

(B134) No. 46 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the ground short circuit of harness between ECM connector and common rail pressure sensor connector.

5.CHECK POOR CONTACT.

Check for poor contact of the ECM connector and the common rail pressure sensor connector.

Is there poor contact of ECM connector or common rail pressure sensor connector?

Repair the poor contact of ECM connector or common rail pressure sensor connector.

Replace the common rail assembly.