Inspection steps

NOTE: Read the freeze frame data using the SSM4. A part of the engine running conditions under which the engine trouble occurred is recorded in the freeze frame data, which is useful for troubleshooting.

Reading of SSM4 data

Connect the SSM4 to the DLC3.
Turn the ignition switch to ON with engine stopped.
Turn on the SSM4.
Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Data monitor]/[Mani. Absolute Pressure]
Read [Mani. Absolute Pressure].
Criteria: Indicates a value almost equal to the actual barometric pressure.

MANIFOLD ABSOLUTE PRESSURE REFERENCE

Inspection conditions	[Mani. Absolute Pressure]
IG ON, engine stop	80 to 110 kPa

NOTE: Normal barometric pressure is 101 kPa {758 mmHg}. As altitude increases 100 m {328 ft}, the atmospheric pressure decreases 1 kPa. This rate of change depends on the weather.

RESULT REFERENCE

Result	Go to
Malfunction	A
Normal	B

B: Inspection for problems that do not normally occur (Refer to Checking/clearing DTC )

A: Go to next step

Check wiring harness and connector (air pressure sensor ASSY power supply voltage check)

NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to Inspection procedures for electrical circuits and how to perform .

Disconnect the connector for air pressure sensor ASSY.
Measure the voltage between the terminals.

VOLTAGE SPECIFICATIONS

Inspection terminals	Inspection conditions	Standard value
C18-3(VC)- C18-1(E2)	IG ON	4.5 to 5.5 V
C18-2 (PIM) - C18-1 (E2)	IG ON	4.0 to 5.0 V

Fig 1: Air Pressure Sensor Assy Connector End View

Courtesy of SUBARU OF AMERICA, INC.

NG: Go to Step 6.

OK: Go to Next Step.

Replacement of air pressure sensor ASSY
1. Replace the air pressure sensor ASSY. (Refer to Removal )
Next
Clear DTC
1. Connect the SSM4 to the DLC3.
2. Turn the ignition switch to ON.
3. Turn on the SSM4.
4. Follow the SSM4 on-screen instructions to clear the DTCs. (Refer to Checking/clearing DTC )
Next

Perform test drive for operation check

Perform test drive. (Refer to "Test drive " under "Description of functions")
Connect the SSM4 to the DLC3.
Turn the ignition switch to ON.
Turn on the SSM4.
Follow the SSM4 on-screen instructions to check the DTCs. (Refer to Checking/clearing DTC )

RESULT REFERENCE

Result	Go to
P0107 or P0108 is output.	A
No DTC is output	B

B: Complete

A: Replacement of the engine control computer (Refer to Removal )

Check wiring harness and connector (air pressure sensor ASSY - engine control computer)

NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to Inspection procedures for electrical circuits and how to perform .

Disconnect the connector for air pressure sensor ASSY.
Disconnect the connector for the engine control computer.
Measure the resistance between the terminals. (For terminal arrangement, refer to ECM terminal arrangement .)

RESISTANCE SPECIFICATIONS (OPEN CIRCUIT CHECK)

Inspection terminals	Inspection conditions	Standard value
A36-19 (VC) - C18-3 (VC)	Always	Less than 1 Ω
A34-20 (PIM) - C18-2 (PIM)	Always	Less than 1 Ω
A36-29 (E1) - C18-1 (E2)	Always	Less than 1 Ω

RESISTANCE SPECIFICATIONS (SHORT CIRCUIT CHECK)

Inspection terminals	Inspection conditions	Standard value
A36-19 (VC) and C18-3 (VC) - other terminals and chassis ground	Always	10 k Ωor more
A34-20 (PIM) and C18-2 (PIM) - other terminals and chassis ground	Always	10 k Ωor more
A36-29 (E1) and C18-1 (E2) - other terminals and chassis ground	Always	10 k Ωor more

NG: Repair or replacement of wiring harness or connector

OK: Replacement of the engine control computer (Refer to Removal )