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

WIRING DIAGRAM:

LHD model

RHD model

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1.CHECK INPUT SIGNAL OF ECM.

Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B134) No. 19 (+) — Chassis ground (−):

Is the voltage 4.5 V or more?

2.CHECK INPUT SIGNAL OF ECM.

Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B134) No. 19 (+) — Chassis ground (−):

Does the voltage change by shaking the harness and connector of ECM while monitoring the value on voltage meter?

Repair the poor contact of ECM connector.

Contact with SUBARU distributor service.

3.CHECK INPUT SIGNAL OF ECM.

Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B134) No. 6 (+) — Chassis ground (−):

Is the voltage 4.5 V or more?

Contact with SUBARU distributor service.

4.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) Turn the ignition switch to ON.

4) Measure the voltage between manifold absolute pressure sensor connector and engine ground.

Connector & terminal

(E21) No. 3 (+) — Engine ground (−):

Is the voltage 4.5 V or more?

Repair the open circuit of harness between ECM and manifold absolute pressure sensor connector.

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

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from the ECM.

3) Measure the resistance of harness between ECM and manifold absolute pressure sensor connector.

Connector & terminal

(B134) No. 6 — (E21) No. 1:

Is the resistance less than 1 Ω?

Repair the open circuit of harness between ECM and manifold absolute pressure sensor connector.

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

Measure the resistance of harness between ECM and manifold absolute pressure sensor connector.

Connector & terminal

(B134) No. 29 — (E21) No. 2:

Is the resistance less than 1 Ω?

Repair the open circuit of harness between ECM and manifold absolute pressure sensor connector.

7.CHECK POOR CONTACT.

Check poor contact of 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.