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

DTC P0108 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE CIRCUIT HIGH INPUT

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 intake manifold absolute 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 procedure, refer to the general scan tool operation manual.

Is the measured value 119.5 kPa (896.5 mmHg, 35.29 inHg) or more?

Even if the malfunction indicator light illuminates, 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 HARNESS BETWEEN ECM AND MANIFOLD ABSOLUTE PRESSURE SENSOR CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from manifold absolute pressure sensor.

3) Start the engine.

4) Read the data of intake manifold absolute 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 procedure, refer to the general scan tool operation manual.

Is the measured value 119.5 kPa (896.5 mmHg, 35.29 inHg) or more?

Repair the short circuit of harness to power supply between ECM and manifold absolute pressure sensor connector.

3.CHECK HARNESS BETWEEN ECM AND MANIFOLD ABSOLUTE PRESSURE SENSOR CONNECTOR.

1) Turn the ignition switch to OFF.

2) Measure the resistance of harness between manifold absolute pressure sensor connector and engine ground.

Connector & terminal

(E21) No. 1 — Engine ground:

Is the resistance less than 5 Ω?

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit of harness between ECM and manifold absolute pressure sensor connector.

• Poor contact in ECM connector

• Poor contact in coupling connector

4.CHECK POOR CONTACT.

Check for poor contact in manifold absolute pressure sensor connector.

Is there poor contact in manifold absolute pressure sensor connector?

Repair the poor contact of manifold absolute pressure sensor connector.

Replace the manifold absolute pressure sensor.