DTC C1983: High Frequency Operation

DTC detecting condition: 

This malfunction is stored if the electronic parking brake is operated with high frequency in a short period of time.

Trouble symptom: 

Parking brake system does not operate sometimes.

1. CHECK OUTPUT OF AMBIENT SENSOR USING SUBARU SELECT MONITOR  .
   1. Turn the ignition switch to ON.
   2. Using Subaru Select Monitor, display [Ambient Temp Sensor] of [Data Monitor], Ref. to BRAKE CONTROL (DIAGNOSTICS)>DATA MONITOR .

   Is the reading of [Ambient Temp Sensor] within the range of ±10°C to the ambient temperature?

   Yes:  Go to  2.

   No:  Repair the ambient sensor circuit.

2. CHECK VDCCM & H/U  .
   1. Turn the ignition switch to OFF.
   2. Stop the vehicle for approximately one hour.
   3. Turn the ignition switch to ON.
   4. Using the Subaru Select Monitor, perform the clear memory. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY .
   5. Execute the inspection mode. Ref. to BRAKE CONTROL (DIAGNOSTICS)>INSPECTION MODE .
   6. Read the DTC using Subaru Select Monitor, Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is the same DTC displayed?

   Yes:  Replace the VDCCM & H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .

   No:  Go to  3.

3. CHECK DETECTION OF OTHER DTCS FOR VDC  .

   Read the DTC using Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is any other DTC displayed?

   Yes:  Perform the diagnosis according to the DTC. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

   No:  Currently, it is normal. There may have been a temporary poor contact in the harness and connector or a temporary noise interference.