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P0446

AJ: DTC P0446 - EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL LOW INPUT

DTC DETECTING CONDITION:
- Two consecutive driving cycles with fault.

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





WIRING DIAGRAM

10AJ1: CHECK OUTPUT SIGNAL FROM ECM.
1. Turn ignition switch to ON.

Connector & Terminal (B134) No.10 (+) - Chassis ground (-):




2. Measure voltage between ECM and chassis ground.

CHECK: Is the voltage more than 10 V?

YES: Go to step 10AJ2.

NO: Go to step 10AJ3.

10AJ2: CHECK POOR CONTACT.
Check poor contact in ECM connector.

CHECK: Is there poor contact in ECM connector?

YES: Repair poor contact in ECM connector.

NO: Even if MIL lights up, the circuit has returned to a normal condition at this time. (However, the possibility of poor contact still remains.)

NOTE:
In this case, repair the following:
- Poor contact in drain valve connector.
- Poor contact in ECM connector.
- Poor contact in coupling connectors (B97, B98 and R57).

10AJ3: CHECK HARNESS BETWEEN DRAIN VALVE AND ECM CONNECTOR.
1. Turn ignition switch to OFF.
2. Disconnect connectors from drain valve and ECM.

Connector & Terminal (R69) No.2 - Chassis ground:




3. Measure resistance of harness between drain valve connector and chassis ground.

CHECK: Is the resistance less than 10 ohms?

YES: Repair ground short circuit in harness between ECM and drain valve connector.

NO: Go to step 10AJ4.

10AJ4: CHECK HARNESS BETWEEN DRAIN VALVE AND ECM CONNECTOR.

Connector & Terminal (B134) No.10 - (R69) No.2:




Measure resistance of harness between ECM and drain valve connector.

CHECK: Is the voltage less than 1 ohm?

YES: Go to step 10AJ5.

NO: Repair harness and connector.

NOTE:
In this case, repair the following:
- Open circuit in harness between ECM and drain valve connector
- Poor contact in coupling connectors (B98 and R57)

10AJ5: CHECK DRAIN VALVE

Terminals No.1 - No.2:




Measure resistance between drain valve terminals.

CHECK: Is the resistance between 10 and 100 ohm?

YES: Go to step 10AJ6.

NO: Replace drain valve.

10AJ6: CHECK POWER SUPPLY TO DRAIN VALVE.
1. Turn ignition switch to ON.

Connector & Terminal (R69) No.1 (+) - Chassis ground (-):




2. Measure voltage between drain valve and chassis ground.

CHECK: Is the voltage more than 10 V?

YES: Go to step 10AJ7.

NO: Repair harness and connector.

NOTE:
In this case, repair the following:
- Open circuit in harness between main relay and drain valve.
- Poor contact in coupling connectors (B97 and R57).
- Poor contact in main relay connector.

10AJ7: CHECK POOR CONTACT.
Check poor contact in drain valve connector.

CHECK: Is there poor contact in drain valve connector?

YES: Repair poor contact in drain valve 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.