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DTC P1110 - ATMOSPHERIC PRESSURE SENSOR CIRCUIT LOW INPUT

DTC DETECTING CONDITION:
- Immediately at fault recognition

CAUTION: After repair or replacement of faulty parts, conduct CLEAR MEMORY MODE and INSPECTION MODE. Refer to How To Clear Diagnostic Trouble Codes.

Wiring Diagram:





WIRING DIAGRAM

11BP1: CHECK CURRENT DATA.

1. Start engine.
2. Read the data of intake manifold absolute pressure signal using Subaru Select Monitor or OBD-II general scan tool.

NOTE:
- Subaru Select Monitor
For detailed operation procedure, refer to the "READ CURRENT DATA SHOWN ON DISPLAY FOR ENGINE". Refer to Normal Scan Data Values.
- OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II General Scan Tool Instruction Manual.

CHECK: Is the value less than 0 kPa (0 mmHg, 0 inHg)?

YES: Go to step 11BP3.

NO: Go to step 11BP2.

11BP2: CHECK POOR CONTACT.
Check poor contact in ECM and pressure sensor connector.

CHECK: Is there poor contact in ECM or pressure sensor connector?

YES: Repair poor contact in ECM or atmospheric pressure sensor connector.

NO: Even if MIL lights up, the circuit has returned to a normal condition at this time.

11BP3: CHECK INPUT SIGNAL FOR ECM.

Connector & Terminal - [(B136) No.15 (+) - Chassis Ground (-)]:





Measure voltage between ECM connector and and chassis ground.

CHECK: Is the voltage more than 4.5 V?

YES: Go to step 11BP5.

NO: Go to step 11BP4.

11BP4: CHECK INPUT SIGNAL FOR ECM.

Connector & Terminal - [(B136) No.15 (+) - Chassis Ground (-)]:





Measure voltage between ECM connector and chassis ground.

CHECK: Does the voltage change more than 4.5 V by shaking harness and connector of ECM while monitoring the value with voltage meter?

YES: Repair poor contact in ECM connector.

NO: Contact with Subaru of America (SOA) service.

NOTE: Inspection by Subaru of America's DTM is required, because probable cause is deterioration of multiple parts.

11BP5: CHECK INPUT SIGNAL FOR ECM.

Connector & Terminal - [(B136) No.29 (+) - Chassis Ground (-)]:





Measure voltage between ECM and chassis ground.

CHECK: Is the voltage less than 0.2 V?

YES: Go to step 11BP7.

NO: Go to step 11BP6.

11BP6: CHECK INPUT SIGNAL FOR ECM. (USING SUBARU SELECT MONITOR.)
Read data of atmospheric absolute pressure signal using Subaru Select Monitor.

NOTE:
- Subaru Select Monitor
For detailed operation procedure, refer to the READ CURRENT DATA SHOWN ON DISPLAY FOR ENGINE". Refer to Normal Scan Data Values.

CHECK: Does the value change more than 0 kPa (0 mm Hg, 0 inHg) by shaking harness and connector of ECM while monitoring the value with Subaru select monitor?

YES: Repair poor contact in ECM connector.

NO: Go to step 11BP7.

11BP7: CHECK HARNESS BETWEEN ECM AND ATMOSPHERIC PRESSURE SENSOR CONNECTOR.

1. Turn ignition switch to OFF.
2. Disconnect connector from atmospheric pressure sensor.
3. Turn ignition switch to ON.

Connector & Terminal - [(B2) No.3 (+) - Engine Ground (-)]:





4. Measure voltage between atmospheric pressure sensor connector and engine ground.

CHECK: Is the voltage more than 4.5 V?

YES: Go to step 11BP8.

NO: Repair harness and connector.

NOTE: In this case, repair the following:
- Open circuit in harness between ECM and atmospheric pressure sensor connector
- Poor contact in joint connector (B83)

11BP8: CHECK HARNESS BETWEEN ECM AND ATMOSPHERIC PRESSURE SENSOR CONNECTOR.

1. Turn ignition switch to OFF.
2. Disconnect connector from ECM.

Connector & Terminal - [(B136) No.16 - (B2) No.1]:





3. Measure resistance of harness between ECM and pressure sensor connector.

CHECK: Is the resistance less than 1 Ohm?

YES: Go to step 11BP9.

NO: Repair harness and connector.

NOTE: In this case, repair the following:
- Open circuit in harness between ECM and pressure sensor connector

11BP9: CHECK HARNESS BETWEEN ECM AND ATMOSPHERIC PRESSURE SENSOR CONNECTOR.

Connector & Terminal - [(B2) No.2 - Engine Ground]:





Measure resistance of harness between pressure sensor connector and engine ground.

CHECK: Is the resistance more than 500 K.Ohms?

YES: Go to step 11BP10.

NO: Repair ground short circuit in harness between ECM and pressure sensor connector.

11BP10: CHECK POOR CONTACT.
Check poor contact in pressure sensor connector.

CHECK: Is there poor contact in pressure sensor connector?

YES: Repair poor contact in atmospheric pressure sensor connector.

NO: Replace atmospheric pressure sensor.