DTC P0108: Manifold Absolute Pressure/Barometric Pressure Sensor Circuit High: Notes

WARNING: This page is about a different variant/trim than selected.

-
DTC detecting condition:

Immediately at fault recognition

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM (IMPREZA MODEL)>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .
- IMPREZA MODEL
Courtesy of SUBARU OF AMERICA, INC.
- CROSSTREK MODEL
Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

CHECK DATA MONITOR .
1. Start the engine.
2. Using the Subaru Select Monitor or a general scan tool, read the value of [Mani. Absolute Pressure].
  NOTE:
  - Subaru Select Monitor For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON (DIAG)>DATA MONITOR .
  - General scan tool For detailed operation procedures, refer to the general scan tool operation manual.
  Is the value of [Mani. Absolute Pressure] 111.5 kPa (836.5 mmHg, 32.93 inHg, 16.17 psi) or more?
  
  Yes: Go to 2.
  
  No: 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, temporary open or short circuit of harness may be the cause.
CHECK HARNESS BETWEEN ECM AND MANIFOLD ABSOLUTE PRESSURE SENSOR (SHORT TO POWER SUPPLY) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from manifold absolute pressure sensor.
3. Start the engine.
4. Using the Subaru Select Monitor or a general scan tool, read the value of [Mani. Absolute Pressure].
  NOTE:
  - Subaru Select Monitor For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON (DIAG)>DATA MONITOR .
  - General scan tool For detailed operation procedures, refer to the general scan tool operation manual.
  Is the value of [Mani. Absolute Pressure] 125 kPa (937.7 mmHg, 36.92 inHg, 18.12 psi) or more?
  
  Yes: Repair the short circuit to power in harness between ECM connector and manifold absolute pressure sensor connector.
  
  No: Go to 3.
CHECK HARNESS BETWEEN ECM AND MANIFOLD ABSOLUTE PRESSURE SENSOR (OPEN) .
1. Turn the ignition switch to OFF.
2. Measure the resistance of harness between manifold absolute pressure sensor connector and engine ground.
  Connector and terminal
  
  (E21) No. 2 - Engine ground:
  
  Is the resistance less than 5 Ω?
  
  Yes: Go to 4.
  
  No: Repair the harness and connector.
  NOTE:
  In this case, repair the following item:
  - Open circuit of harness between ECM connector and manifold absolute pressure sensor connector
  - Poor contact of ECM connector
  - Poor contact of J/C
CHECK FOR POOR CONTACT .
Check for poor contact of manifold absolute pressure sensor connector.

Is there poor contact of manifold absolute pressure sensor connector?

Yes: Repair the poor contact of manifold absolute pressure sensor connector.

No: Replace the manifold absolute pressure sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO (EXCEPT FOR HEV))>MANIFOLD ABSOLUTE PRESSURE SENSOR .