DTC P1C31: Invalid Data Received From Drive Motor Inverter: Trouble Symptom

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.

EV traveling/Auto Start Stop does not operate.
Motor assist does not regenerates.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". < Ref. to CAUTION , General Description.>

DTC PROCEDURE

Step	Check	Yes	No
1 CHECK DTC. Read the DTC. < Ref. to DRIVE MOTOR CONTROL SYSTEM , OPERATION, Read Diagnostic Trouble Code (DTC).>	Is DTC P1C31 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 GROUND WIRE. 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. Check the fastening area shown in the margin.	Is the condition normal? (Check for loose bolts, insecure connection, foreign matter caught, etc.)	Go to step 3 .	Retighten the bolts. Or replace the harness.
3 CHECK DRIVE MOTOR INVERTER. Replace the drive motor inverter. < Ref. to INVERTER .> 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 drive motor inverter.

NOTE:

Fig 1: Identifying Underside DMCM

Courtesy of SUBARU OF AMERICA, INC.