DTC P1F00: Self-Shut Off Relay Circuit Low: Notes

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DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Drivability getting worse.

Wiring diagram:

AWD control system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>AWD CONTROL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

CHECK HARNESS .
1. Disconnect the AWD control module connector.
2. Remove the AWD control module relay.
3. Measure the resistance between AWD control module connector and relay holder.
Connector and terminal

(B648) No. 18 - (B225) No. 36:

(B648) No. 2 - (B225) No. 38:

(B648) No. 15 - (B225) No. 38:

Is the resistance less than 1 Ω?

Yes: Go to 2.

No: Repair the open circuit of harness.
CHECK HARNESS .
Measure the resistance between AWD control module connector and chassis ground.

Connector and terminal

(B648) No. 18 - Chassis ground:

(B648) No. 2 - Chassis ground:

(B648) No. 15 - Chassis ground:

Is the resistance 1 MΩ or more?

Yes: Go to 3.

No: Repair the short circuit of harness.
CHECK RELAY POWER SUPPLY .
Measure the voltage between relay holder and chassis ground.

Connector and terminal

(B225) No. 35 (+) - Chassis ground (-):

(B225) No. 37 (+) - Chassis ground (-):

Is the voltage 10 V or more?

Yes: Go to 4.

No: Repair the open or short circuit of harness.
CHECK AWD CONTROL MODULE RELAY .
Measure the resistance between the AWD control module relay terminals.

Connector and terminal

No. 35 - No. 36:

Is the resistance 70 - 180 Ω?

Yes: Go to 5.

No: Replace AWD control module relay.
CHECK AWD CONTROL MODULE RELAY .
Measure the resistance between the AWD control module relay terminals.

Connector and terminal

No. 37 - No. 38:

Is the resistance 1 MΩ or more?

Yes: Go to 6.

No: Replace AWD control module relay.
REPLACE AWD CONTROL MODULE RELAY .
1. Replace AWD control module relay.
2. Connect the AWD control module connector.
3. Using the Subaru Select Monitor, read data of [Main Power Supply Voltage] in the [Data Monitor] of [AWD Control]. Ref. to AWD CONTROL (DIAGNOSTICS)>DATA MONITOR .
Is [Main Power Supply Voltage] 10 V or more?

Yes: Check for poor contact of AWD control module connector. Replace the AWD control module if no fault is found. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TH2A)>AWD CONTROL MODULE .

No: AWD control module relay is defective.