DTC P1C34: Lost Communication With Dc/Dc Converter: Wiring Diagram

WARNING: This page is about a different car, the 2015 Subaru XV Crosstrek. However, it is still accessible from the selected car via links, so may be relevant.

Hybrid system < Ref. to WIRING DIAGRAM , Hybrid Electric Vehicle System.>

Fig 1: Manufacturer Controlled DTC - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DTC PROCEDURE

Step	Check	Yes	No
1 CHECK DTC. Start the engine. Read the DTC. < Ref. to DRIVE MOTOR CONTROL SYSTEM , OPERATION, Read Diagnostic Trouble Code (DTC).>	Is DTC P1C34 detected? (current malfunction)	Go to step 2 .	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.
2 CHECK CONNECTOR. Turn the ignition to OFF. Disconnect the ground cable of the 12 volt auxiliary battery, and as for the 12 volt engine restart battery, disconnect the ground cable from the 12V engine restart battery sensor. < Ref. to BATTERY , NOTE, Note.> Remove the service disconnect plug. < Ref. to SERVICE PLUG .> Wait for 10 minutes. Visually check each connector and fastening areas of the DC/DC converter.	Is the condition normal? (Check for loose bolts, insecure connection, foreign matter caught, etc.)	Go to step 3 .	Repair or replace faulty parts.
3 CHECK HARNESS. Disconnect the DC/DC converter connector. Disconnect the DMCM connector. Using a tester, measure the resistance between DMCM connector and the ground bolt of inverter frame body. Connector & terminal (R443) No. 20 - Ground bolt of inverter frame body:	Is the resistance 1 MΩ or more?	Go to step 4 .	Repair short to ground circuit in harness between DMCM connector and DC/DC converter connector, or repair the intermediate connector.
4 CHECK HARNESS. Using a tester, measure the resistance between DC/DC converter connector and DMCM connector. Connector & terminal (R443) No. 20 - (R433) No. 3:	Is the resistance less than 1 Ω?	Go to step 5 .	Repair open circuit in harness between DMCM connector and DC/DC converter connector, or repair the intermediate connector.
5 CHECK HARNESS (SHORT TO OTHER SIGNAL). Disconnect the drive motor inverter connector. Disconnect the intermediate connector (R436). Using a tester, measure the resistance between DMCM connector and individual connectors of drive motor inverter. Connector & terminal: (R443) No. 20 - (R442) No. 1 - 22: (R443) No. 20 - (R443) No. 1 - 26: (R443) No. 20 - (R436) No. 1 - 8: (R443) No. 20 - (R432) No. 7:	Is the resistance 1 MΩ or more?	Go to step 6 .	Repair short circuit in harness between DMCM connector and DC/DC converter connector, or repair the intermediate connector.
6 CHECK HARNESS (SHORT TO POWER). Using a tester, measure the resistance between DC/DC converter connector and DC/DC converter 12 V output line. Connector & terminal (R433) No. 3 - DC/DC converter 12 V output line:	Is the resistance 1 MΩ or more?	Go to step 7 .	Repair short circuit in harness between DMCM connector and DC/DC converter 12 V output line or repair the intermediate connector.
7 CHECK DC/DC CONVERTER. Replace the DC/DC converter. < Ref. to DC/DC CONVERTER .> Perform the Inspection Mode. < Ref. to INSPECTION MODE .>	Is the same DTC detected? (current malfunction)	Replace DMCM. < Ref. to appropriate DRIVE MOTOR CONTROL MODULE in Continuously Variable Transmission TH58A article.>	Problem is present in DC/DC converter.